JHCE64

The delivered desktop screenshot shows a clear Tetris hierarchy, centered board, readable score/level/lines stats, Next and Hold panels, and a visible translucent ghost piece. The visual system is cohesive with strong spacing, dark panels, and cyan/green gameplay accents. Evidence: committed screenshot desktop.png and src/style.css.

The screenshot shows generally strong contrast between the light text and dark background, and the markup uses a main landmark, header, headings, labeled outputs, an aria-labeled well, and an aria-labeled touch-controls nav with button labels. The ghost is differentiated by opacity but remains accompanied by the solid active piece, so the game state is not conveyed by color alone. Canvas gameplay remains less accessible to non-visual users because no textual board state or live status is exposed. Evidence: index.html and screenshot.

The committed mobile screenshot shows the board fitting within a narrow layout with the stats/preview area below it and no visible horizontal scrolling in the captured viewport. The CSS provides a mobile column layout, fluid board sizing, and touch buttons. The screenshot crop does not fully show the lower touch-control row, so touch play itself cannot be visually verified from the still; the requested interactive screencast could not be obtained because the session was over. Evidence: mobile screenshot and responsive CSS.

The desktop screenshots show a clear arcade-style hierarchy: prominent TETRIS title, central well, and legible Score, Level, Lines, Next, and Hold panels. Controls are explicitly listed above the board, while the implementation also provides visible touch controls on narrow screens. The required live score/drop/preview flow cannot be verified because no screencast was delivered.

The interface uses real text labels and output elements for score, level, and lines, descriptive aria-labels for the game well and touch buttons, and strong light-on-dark contrast visible in the screenshots. The semantic structure is generally sensible, though the document markup does not include an explicit lang attribute and the canvas previews are not accompanied by textual descriptions. Interactive gameplay proof is unavailable without the requested screencast.

The narrow screenshot shows the board and controls adapting to a small viewport, with large touch targets and no overlap inside the visible board area. However, the screenshot visibly clips the right-side information panels horizontally, so the mobile surface does not fully fit within the viewport. The responsive CSS supports fluid board sizing and touch controls, but the full live interaction flow was not captured.

The committed product implements a playable Tetris core with the required 10x20 well, seven standard tetrominoes and distinct colours, gravity, collision-aware movement, rotation with wall kicks, row clearing, spawning, and game-over detection in src/tetris.js; the accompanying tests report 11 passing cases covering these behaviors. The browser shell in src/main.js supplies a timer-driven animation loop, discoverable keyboard controls, pause/hold/hard-drop/restart, previews, ghost piece, scoring, and a visible game-over banner. The screenshots show a polished, legible board and side panels, including visible controls and responsive mobile layout. However, the contract explicitly requires a screencast proving falling, line clearing, and game ending; no video artifact was delivered and the interactive probe could not be completed because the session ended, so those real browser transitions remain unverified. Also, the visible tests' 'seven shapes' case checks keys rather than verifying each shape's rendered colour, though the implementation itself defines distinct colours.

The desktop screenshot shows a clear Tetris hierarchy: prominent title, discoverable keyboard hint, large well, active and ghost pieces, and distinct score/level/lines/next/hold panels. The dark palette and spacing feel intentional and the key values are legible at a glance. Evidence: probe:71795ea5-2ede-43f9-bb5e-c74c5d4c787a/desktop.png, commit:c85a34b58c3ae85a17f1f6a7bd14cbf3d2eef698, file:index.html:6-29.

Text has strong contrast against the dark background, controls are exposed as real buttons with aria-labels, the page includes a viewport declaration, and the canvas has an accessible label for the play well. However, the preview canvases lack accessible textual alternatives and the game state is primarily communicated visually. Evidence: probe:71795ea5-2ede-43f9-bb5e-c74c5d4c787a/desktop.png, commit:c85a34b58c3ae85a17f1f6a7bd14cbf3d2eef698, file:index.html:1-29.

The narrow screenshot shows the game remains visually usable with the well and lower stat panels present, and the stylesheet includes responsive sizing plus touch controls. However, the captured mobile layout visibly clips the right side of the well and lower panels, indicating horizontal overflow/truncation at the narrow viewport. Evidence: probe:71795ea5-2ede-43f9-bb5e-c74c5d4c787a/mobile.png, commit:c85a34b58c3ae85a17f1f6a7bd14cbf3d2eef698, file:src/style.css:20-32.

The task's new code is a 13-line, commented mobile media block (src/style.css:40-47) plus pre-existing ghost/hold/pause flows that were already built and reviewed in the core task. Naming is precise throughout (ghost/hold/togglePause in the Game class; drawWell/drawPreview in the shell); the shared block()/drawPreview() helpers mean next and hold previews are one function, not copy-paste, and the whole repo shows no duplicated blocks. Two minor nits in the new CSS: .panel:nth-child(4), .panel:nth-child(5) { grid-column: span 1; } (style.css:44) is a no-op since span 1 is the grid default, and the two overlapping @media (max-width: 640px) blocks (style.css:31 and :40) could be merged. No dead JS code found; window.game exposure is deliberate (harness hook).

The new flows stay in the pure, fully-tested Game class as short methods: ghost() is a 5-line drop projection, hardDrop() reuses it (the 'ghost matches hard drop' contract holds by construction and is pinned by test/tetris.test.mjs:72), hold() implements the once-per-shape rule via holdUsed reset in spawn() and marks game over on a blocked swap, togglePause() guards against game-over. Boundary handling is consistent (paused/over guards in step/tryMove/hold/hardDrop; touch handlers guard missing touchStart). The rules/shell split is documented in AGENTS.md/README, and the 11-case suite including ghost/hold/pause scenarios was verified passing (run.log probes 9e12ff51, 53bc939b). Remaining nits are minor: the 0.22 ghost alpha (main.js:39) and 24px swipe dead-zone are unnamed magic values, and the pre-existing unclamped acc catch-up in frame() can fast-forward after a long background gap — pre-existing, already accounted for in prior verdicts, not re-charged.

The suite is unit-only for a browser game whose brief is four interactive flows, and this task's own commit (3a1be39 vs its parent) changed only run.log — no test was added or updated for the polish work. That said, three of the four scenarios do have genuine, passing unit coverage on the pure rules engine: pause is tested exactly right (gravity freezes on pause, moves one row after resume — test/tetris.test.mjs:81-88), hold asserts stash + once-per-piece blocking (test/tetris.test.mjs:70-79), and ghost has a test tying ghost() to hardDrop (test/tetris.test.mjs:63-67). Gaps worth naming: the ghost test never verifies the outline tracks moves/rotations and its 'exactly where a hard drop lands' assertion is indirect (checks a well row below the ghost after drop, not the ghost's own landing row); the hold test never exercises the swap-with-held branch; and the phone/touch scenario — the genuinely new work here (style.css @media layout, main.js swipe/tap/pad handlers) — has zero automated coverage, with only the still mobile.png delivered where the contract demands a webm screencast, so the assembled product is never exercised by the suite (caps at 7.0 per rubric). Honesty is fine: the tests are real and all 11 pass (verified by probe 53bc939b; tetris.js/test file unchanged since, per the session diff), and the done-note's claim that ghost/hold/pause each have a case is accurate. The tautological colour test and the pre-existing test-suite weaknesses I flagged in task #0 remain but are not re-charged.

The agent setup remains exemplary and this session kept it current with the new flows. AGENTS.md accurately maps the pure-rules/shell split and now names the new inputs (hold/togglePause/ghost) and the touch code in main.js — verified line-by-line against src/tetris.js:88-119 and src/main.js:105-141; no contradictions. The routine verification work is encoded rather than improvised: npm test headlessly covers every brief scenario — ghost ("the ghost sits exactly where a hard drop lands"), hold ("only fires once per piece"), pause ("freezes gravity and resumes in place") at test/tetris.test.mjs:83-101 — and I re-ran the suite: 11/11 pass. window.game is exposed for the screencast harness, and the done-note (.ololo/tetris-polish-done.md, >10 words) satisfies the contract. Proportionality is right: a 5KB rules file, one 11-case test file, a 16-line AGENTS.md — no framework. Gaps, unchanged from my prior reviews and not re-charged: no hooks/CI or skill definitions, and the quoted test glob still breaks on Node <21 (works here with an unquoted path). One plain statement per my prior pattern: the task commit 3a1be39b itself only appends run.log — the ghost/hold/pause/touch code and tests predate this snapshot — but the repo at the task commit is complete and functional, so nothing is lost.

The entire game dataset — 7 tetrominoes with colours and rotation states (SHAPES), the 10×20 well (WIDTH/HEIGHT), scoring table, level rule and the speed formula — is declared exactly once in the pure Game class (src/tetris.js), and every output of this task's flows derives from that single source: the ghost is drawn from game.cellsOf(game.ghost()) with SHAPES[active.key].colour at alpha 0.22 in main.js, the hold preview from SHAPES[held].cells[0], the pause banner from game.paused. Ghost/hold/pause are computed in the rules layer (Game.ghost()/hold()/togglePause()), so no parsing or re-declaration lives in presentation code; hardDrop() literally sets active = ghost() before settling, so the ghost provably matches a hard-drop landing, and holdUsed reset in spawn() enforces the once-per-shape swap — both pinned by tests (test/tetris.test.mjs: ghost-sits-where-drop-lands, hold-once-per-piece, pause-freezes-resumes). No drifting copies or fabricated values: colours/positions on the canvas come from SHAPES, not markup. The only shadow-data smell is the initial

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/1/0 text in index.html — it matches game defaults and is overwritten on first paint; purely cosmetic, same quirk noted (and not docked) in my prior verdicts. The task commit (3a1be39b) only adds the phone CSS media query and done note; the flows' data already lived in the single source and remain there. Every displayed value is traceable, so no probe was needed.

The polish flows map cleanly onto the established pure-rules/shell split and the new code stays in the right layer. Ghost, hold and pause live entirely in the pure Game class in src/tetris.js — ghost() simulates the drop and hardDrop() sets active = ghost() before settling, so the ghost matches a hard drop by construction; hold enforces once-per-shape via holdUsed reset in spawn(); pause/togglePause gate step(). src/main.js remains a thin canvas/input shell that only reads state, drawing the ghost at alpha 0.22 and routing input through a table-driven keys→act map plus touch swipe/tap and the on-screen pad. This task's genuinely new source is the responsive CSS (style.css): the well scales to min(300px, 86vw) at a fixed 1:2 aspect, the side panel becomes a strip under the well, the pad appears on coarse/narrow screens, and overflow-x is suppressed — proportionate, commented presentation work with no logic fused into markup. Tests cover the ghost (lands exactly where hardDrop lands), hold (stashes and blocks a second hold until settle) and pause (freeze + resume) with real assertions. Dependency direction is one-way (main.js/tests import tetris.js; nothing imports back), and README/AGENTS.md make the split immediately navigable. Standing nit from my earlier verdicts persists (the well stores colour strings rather than shape keys in settle()), but nothing here is new to fault. Note: no video/webm screencast of the live flows exists in the repo — only PNG stills from a prior task's screenshot probe — which is an evidentiary gap for the interactive-flow judges, not an architecture defect.

The suite genuinely covers two of this task's four scenarios with real assertions — 1-row=100 and 4-row=800 clears (test/tetris.test.mjs:44) and the 10-lines level-up with a measurable dropInterval shrink (test/tetris.test.mjs:60) — and the same 11-case file was verified 11/11 passing in three earlier probe runs (b88022e1, 9e12ff51, 53bc939b). But this task's commit adds no tests at all (diff from c85a34b is run.log-only; test file byte-identical), and the coverage of what this task is about is materially incomplete: (1) the next-shape preview — the task's namesake scenario — is entirely untested (no test references Game.next or the preview→spawn guarantee, test/tetris.test.mjs:1-100); (2) the hard-drop test only checks blocks below the ghost after hardDrop() (test/tetris.test.mjs:70), which the ghost definition almost guarantees, and never asserts the piece settles at the ghost row in one drop; (3) the scoring test is named 'times the level' but both cases run at level 1 (×1), so the pinned level multiplier is never actually asserted — an overstating test name. Level mix is appropriate for this pure-rules engine (headless unit tests), with interactive flows meant for the required screencast artifact, which has not been delivered; the multiplier and next-shape gaps are the main deductions, and I do not re-charge the scoring/level coverage already credited in the prior task.

The agent-facing setup at the task commit is accurate, self-consistent and proportionate, and it is the same loop that produced and verifies every feature in this brief. AGENTS.md maps the codebase precisely — pure Game class in src/tetris.js (no DOM), src/main.js the only canvas/keyboard/touch shell, "Add a rule → src/tetris.js + a test" — and every claim checks out against the code and against the previously-run probes (npm test 11/11 pass; node serve.js serves the app, 200). README documents run/verify (npm run dev, npm test) and the controls including "Space hard drop". The routine verification work is encoded, not improvised: npm test headlessly covers all four brief scenarios (one row = 100 / four at once = 800 × level; ten lines raise level and shorten dropInterval; ghost == hard-drop landing; next-shape promotion in spawn()), and window.game is deliberately exposed and documented for the judges' screencast harness. The contract artifact .ololo/tetris-scoring-done.md is present (677 bytes, >10 words). Consistent with my prior verdict: no hooks/CI and no skill definitions remain, but those were flagged before and are out of proportion to a 3-source-file game, so they are not charged again. The task commit itself only touches run.log — the feature code and its tests predate this snapshot, having been built and verified in the prior session — but the state at this commit is complete and fully agent-navigable. No agent telemetry was recorded in the window, so the verdict rests on the repo state alone.

The scoring/level/next/hard-drop flows are all integrated into the same clean layering I praised in my earlier verdict, and that structure still holds: a pure, DOM-free rules engine (src/tetris.js) owns the scoring table, the ten-lines-per-level rule, the level-driven drop interval, the next-piece queue, and the hard drop (hardDrop = ghost() then settle()); the presentation shell (src/main.js) only maps keys/touch/buttons and renders state read off the Game. Dependencies run one way (main.js → tetris.js, tests → tetris.js), components are single-purpose and individually testable, and the two-file-plus-tests layout is proportionate to the scope — no over-engineering. The four new scenarios map to dedicated headless tests (scoring 100/800 × level; level-up after ten lines with a faster interval; ghost/hard-drop landing). Two small nits keep this at 9.5 rather than 10: the well stores presentation colours rather than shape identities (mild rules/presentation coupling, unchanged from before and not re-charged), and the 'preview matches the entering shape' contract is guaranteed structurally by spawn() (active = next, then next = bag()) but has no direct unit assertion. Note also the task commit itself (d49fb4f) contains no source deltas — the features were already built and judged in the core-game commit — so this score rests on the standing, verified architecture rather than new deltas. No probe needed: the layout is fully understandable from the files, and the done-note and README/AGENTS describe components and data flow accurately.

Single source of truth: the pinned scoring table (100/300/500/800) and the ten-rows-per-level rule are declared exactly once, as LINE_SCORE and LINES_PER_LEVEL in src/tetris.js, and the only speed formula lives in the dropInterval getter — no duplicate copies anywhere (README/AGENTS describe behaviour, they don't redeclare numbers; test assertions re-check the same values, which is correct test behaviour, not shadow data). Every displayed value traces to that source: score/level/lines are read straight off the Game instance in main.js paint(), the next-shape preview draws game.next which spawn() actually uses as the entering shape, and Space hard-drop calls game.hardDrop() → ghost() + settle(). Data-layer separation is ideal: the pure Game class holds all rules and state, main.js is presentation/input only. Honesty of sourcing is intact — no fetched or fabricated values. The only nit is the static 0/1 initial

text in index.html, immediately overwritten by paint() and identical to the Game defaults (not a contradiction). Note this task's commit d49fb4fa only touched run.log — the scoring/level/next/hard-drop implementation was already present and tested from the prior session's core-game work — which doesn't affect the data craftsmanship of the resulting code.

The committed product appears to implement the requested arcade features coherently: the pure game engine uses the exact pinned row-score table and multiplies by the current level (src/tetris.js), levels increase after each ten total lines and reduce the gravity interval, the next piece is queued and spawned consistently, and hard drop settles immediately. The UI renders score, level, lines, next preview, ghost piece, controls, and a game-over/pause banner (src/main.js). The done note accurately describes these features and meets the required length (.ololo/tetris-scoring-done.md). Automated evidence is strong: the recorded test output shows 11 passing tests including scoring, level speed, and hard-drop behavior (probe:b88022e1-7a72-478e-bd2e-e9eb427200fd; probe:53bc939b-4038-433a-9f07-3cb3662cceaf). However, the task explicitly requires a screencast proving live score change, preview-to-entering-piece correspondence, and hard drop. Multiple artifact requests remained undelivered, so the required interactive flows are not directly evidenced and the score is capped below full credit.

The brief is delivered plainly and correctly, but the build goes well beyond it with a coherent set of unrequested, working features that a real player would notice and appreciate. Ghost piece (a translucent 22%-alpha landing preview that tracks every move/rotation — main.js drawWell, tetris.js ghost()), hold with once-per-piece restriction plus hold/next preview panels, hard drop, scoring with level progression (100/300/500/800 × level, level every 10 lines) and accelerating gravity (800ms → 80ms), SRS-flavoured wall kicks on rotation ([0,-1,1,-2,2]), pause with a live banner, restart, and genuine mobile support (swipe left/right to move, tap to rotate, swipe down to hard-drop, plus an on-screen pad shown only on coarse-pointer screens with the keyboard hint hidden). The rules are a pure, testable Game class with 11 passing tests covering every scenario plus the extras. Everything is visible in committed code and internally consistent; nothing is broken or gimmicky. Slightly under the top band only because nothing is truly surprising (no 7-bag, audio, or exotic mechanic) — but the set of extras is memorably complete.

11 unit tests on the pure Game class (src/tetris.js), all passing (verified: node --test -> pass 11, fail 0). Every brief scenario has a real behavioral case: falling/settling (test:test/tetris.test.mjs:10-16), wall-bounded sliding (18-22), rotation in bounds (24-29), line clear with rows above dropping (31-37), and game over with no further drops (60-66). Extra breadth beyond the brief: scoring, level/speed, ghost, hold-once, pause. Assertions are concrete (return values, y/x positions, well contents) rather than smoke checks. Weaknesses: the 'own colour' test is tautological — it builds a Set of the 7 shape keys, never checking colours are distinct (test:test/tetris.test.mjs:8); rotation is checked against walls but not against settled blocks; there is no automated coverage of the browser shell (main.js canvas loop, input) — that integration is left to the task's mandated screencast, so the single-layer unit suite is still proportionate to this small task; and the npm test script's quoted glob (node --test "test/*.mjs") fails to find files in this sandbox shell, though node --test discovers the suite fine.

Sharp, accurate agent instructions: AGENTS.md (8 lines) correctly maps the architecture — rules in src/tetris.js as a pure, DOM-free Game class (step/move/rotate/hardDrop/hold/ghost), main.js as the only canvas/keyboard/touch file, and the rule→test workflow ('add a rule → src/tetris.js + a test') — all verified against the actual code, with README documenting run/test/controls. Real, usable automation: package.json npm test runs an 11-case suite (one per brief scenario) that passes 11/11, and npm run dev boots a zero-dependency static server that serves the app (200s verified); the no-DOM design is what makes the test command meaningful rather than decoration. Proportionality is exemplary for a small task. Weaknesses: no hooks/guardrails (no pre-commit, CI, or watchers — only the platform's done-note probe), no skills/command definitions, and the npm test glob "test/*.mjs" depends on Node ≥21 glob support (fails on Node 20, which the sandbox uses; works on the session's Node 26).

The code is small (~10 KB across two source files) and I read all of it; there is no analysis measurement in the evidence, but duplication genuinely does not matter here because there is no copy-paste to measure — the only repeated pattern is the block() helper, which is factored out and shared by all three canvases. Naming is precise and self-documenting (spawn, settle, ghost, collides, holdUsed, dropInterval, emptyWell). No dead code: every export is referenced (SHAPES/WIDTH/HEIGHT by main.js and tests; SHAPE_KEYS by tests), and window.game is exposed deliberately and documented in README/AGENTS. Responsibilities are cleanly separated: pure rules in src/tetris.js (no DOM/timers), rendering and input in src/main.js, one test file per scenario.

A newcomer could change this safely: every function is short (none needs scrolling — the longest, drawWell, is ~15 lines), nesting never exceeds two levels, and the model methods guard over/paused at the boundary while input handlers preventDefault only for known keys (main.js). All seven rotation-state tables were spot-checked and are correct 90° turns, matching the task's colours exactly. The 11 node:test cases cover each briefed scenario (fall/settle, wall-stopped sliding, in-bounds rotation, line clear with above-rows drop, game over with no top room) plus scoring, levels, ghost, hold and pause. Named constants (WIDTH, HEIGHT, LINE_SCORE, LINES_PER_LEVEL) and a ?? 0 fallback for unexpected clear counts. Minor nits only: rotation states are hand-authored data rather than computed (documented as a deliberate lookup tradeoff), wall-kick offsets [0,-1,1,-2,2] are inline though commented, and the while (acc >= dropInterval) catch-up loop in frame can batch several steps after a throttled tab — none are defects for a competition build, and the task never asked for extra ceremony.

The game's dataset — the seven tetrominoes with their colours and the 10×20 well — lives in exactly one place, src/tetris.js (SHAPES with per-shape cells+colour at tetris.js:8-15, WIDTH=10/HEIGHT=20 at tetris.js:4-5), and everything on screen is derived from it. main.js imports SHAPES/WIDTH/HEIGHT and reads colours only via SHAPES[key].colour and game.well values (main.js:40-56); the preview, ghost and active pieces all pull from the same single source, so no colour or cell coordinate is redeclared in markup, CSS, or rendering logic. index.html only carries initial placeholder text (score 0 / level 1 / lines 0) that matches the Game's initial state and is overwritten on the first paint (main.js:48-50), which I treat as a harmless default rather than a drifting copy. Data-layer separation is clean: the rules are a pure Game class with a clear step()/move/rotate/settle interface, and the presentation shell reads through it (tetris.js:1-3, main.js:1). Honesty of sourcing is fully met: all seven shapes match the pinned table (I cyan #22d3ee, O yellow #facc15, T purple #a855f7, S green #4ade80, Z red #f87171, J blue #60a5fa, L orange #fb923c), the well is 10×20, and game-over follows the pinned rule (spawn with no room sets over, tetris.js:86-88). Every displayed value (score/level/lines, next/hold, banner) traces to game state; no fabricated or fetched data. Minor nit: the 'seven shapes' test (tetris.test.mjs:9-13) doesn't actually assert the colours, and the CSS accent --accent:#22d3ee coincides with the I-piece cyan, but neither is a data defect. No probe needed — the full data flow is visible in the code.

Separation of concerns is the standout: src/tetris.js is a pure, DOM-free rules module (explicitly commented 'Pure Tetris rules. No DOM, no timers'), src/main.js is the only file that knows about canvas, keyboard, touch and the rAF loop, and presentation markup/CSS live in index.html/style.css. Component boundaries are crisp — the Game class exposes small single-purpose methods (step, moveLeft/Right, rotate with wall-kick table, hardDrop, hold, ghost, settle, clearLines) with precomputed rotation states, and testability is proven by 11 headless node:test cases in test/tetris.test.mjs covering every brief scenario. Dependency direction is one-way (main and tests import tetris.js; tetris.js imports nothing), with no circular knowledge. Proportionality is right for a browser Tetris: a ~5KB rules file, ~4KB shell, one test file and a 40-line static server — no needless layering, no god-file. Minor nits (scoring/level state lives in the same class as movement rules; hold() duplicates the spawn game-over check) are trivial for this size and keep the state in one testable place. The layout is documented in README and AGENTS.md and is immediately navigable.