Restructure Tetris Attack Stage Clear from "clear all target panels" to a
multi-stage round system with a sliding boundary line.
Gameplay changes:
- Each character now has 5 stages instead of a single match
- A CLEAR line appears after a set number of rows rise, then rides the
stack upward; the objective is to clear everything above it
- Clearing a stage advances to the next: same board, faster speed, fresh line
- Stage progress is saved to localStorage; characters unlock sequentially
- Added a stage select screen with progress squares per character
Logic changes:
- Replaced `targetsTotal` with `clearLine` tracking and `countAboveLine`
- Added `advanceStage()` to resume play on the same stack one speed level higher
- Win condition now checks `countAboveLine() === 0` instead of target count
- Removed `target` flag from panels; panels below the line are irrelevant
- Continuous speed ramp via fractional `speed` per stage
UI changes:
- Clear line drawn as a pulsing bar with "◀ CLEAR" label outside the board
- "CLEAR LINE!" announcement on appearance, "STAGE N CLEAR!" banner on win
- HUD shows stage number instead of panel count
- Game over offers "Retry Stage", "Stage Select", or "Menu"
Asset changes:
- Backgrounds renamed to `background-{hero}-r{stage}.png` (5 per character)
- Lazy-load backgrounds per round instead of preloading all 30 images
- Updated tetrisattack.json with `stagesPerRound`, `stageSpeedStep`, and
per-character `clearLineRows`
Tests:
- Rewrote stage clear soak tests for the new mechanic
- Added stage round progression, speed ramp, and board preservation tests
Implement the full Tetris Attack clone with three game modes:
- Endless: clear panels as the stack rises, speed increases with levels
- Stage Clear: defeat 6 character opponents (Beth, Jerry, Michael, Steve, Victor, Klaxon) in sequence
- Puzzle: solve 24 pre-vetted puzzles within move limits
Core engine (src/games/tetrisattack/TetrisAttackLogic.js) is a pure, deterministic
state machine with match detection, chain propagation, gravity, and scoring tables
matching the SNES original. Includes a headless verifier (verifyTetrisAttack.js)
testing match detection, chains, gravity invariants, top-out, puzzle solvability,
and seeded determinism.
Art is fully optional via drop-in spritesheets (spec: sprites.md); procedural
fallbacks draw 16-bit-style panel icons with distinct shapes for colorblind access.
Puzzle bank generated by genTetrisAttackPuzzles.js and verified as solvable within
optimal move counts.
Shared nintendo soundtrack reused via soundtrack overrides.
Brian Fertig