Tetris

Cinevva's analyzer read this game's design doc and its source, then wrote the brief below. "Make your own" hands it to the game creator as your opening message, so you start from a real spec rather than a one-line idea.

Create a single-screen, canvas-rendered falling-block puzzle game titled "Tetris" (the in-game side panel should read "BLOCK STACK"). Build the classic 10-column by 20-row playfield with a dark navy/blue theme. The board is a tall rectangular well with a rounded dark border and subtle blue outline; each cell has alternating very dark blue checkerboard shading and thin blue grid lines. Falling and placed tetromino cells are rounded squares with a slight pale highlight near their upper-left corner and a faint light border. Use these seven standard tetrominoes and colors: I cyan (#55e6ff), O yellow (#ffd85c), T purple (#c06cff), L orange (#ffb14d), J blue (#4d8dff), S green (#66e37a), and Z red/pink (#ff616d). Generate pieces using shuffled seven-piece bags, maintain a queue, and show the next piece in a small rounded preview box.

Core gameplay: spawn each tetromino centered near the top of the board, let it automatically fall, and allow horizontal movement, rotation, soft drop, and hard drop. Collision must respect the walls, floor, and locked blocks. Use clockwise matrix rotation with simple wall kicks attempting offsets 0, -1, +1, -2, +2. A falling piece has a translucent ghost projection at its landing position. When a piece can no longer descend, give it about a 450 ms lock delay; then merge it into the board, clear every completed row, shift rows down, and spawn the next piece. Flash completed rows briefly white before the flash ends. Score line clears with [0, 100, 300, 500, 800] for 0 through 4 lines, multiplied by the current level; award 2 points per hard-drop cell and 1 point per soft-drop cell. Increase the level every 10 cleared lines (level = floor(lines/10)+1), and make the automatic fall progressively faster across levels using classic Tetris-like frame intervals, reaching a very fast interval at high levels. If a new piece collides immediately on spawn, end the game.

Desktop layout: center the board toward the left/middle of the viewport and place a rounded information panel immediately to its right. The panel is dark blue with a blue outline and contains large white "BLOCK STACK" text, then vertically stacked Score, Lines, and Level labels in light blue with large white values. On the right side of the panel show "Next" and the upcoming tetromino in a dark rounded preview box. At the bottom of the panel include the instruction text "Move" and "← →  rotate tap". Put a large rounded PAUSE button with white text in the upper-right of the screen. Along the bottom, provide large rounded blue controls: left arrow, down arrow, right arrow at the lower-left, and rotate (circular arrow) plus hard-drop (down arrow) toward the lower-right. Buttons have bright blue outlines, dark blue fills, and lighter active fills when held.

Responsive layout: on narrow portrait screens, put the Score/Lines/Level values in a short horizontal panel above the board, put Next below/in the panel, center the 10x20 board, and keep movement buttons along the bottom with rotate/drop on the right and pause in the upper-right. On narrow landscape screens, keep the board on the left and a compact stats/next panel on the right, with controls beneath. Scale the cell size to fit the viewport while preserving the 10:20 board ratio. Render the entire interface on a full-window canvas with a vertical background gradient from #0d1c31 at the top to #08101c at the bottom.

Controls: keyboard ArrowLeft/ArrowRight or A/D move one cell; hold them for repeated movement on touch/onscreen controls; ArrowDown or S holds soft drop; ArrowUp, W, or X rotates clockwise; Space hard-drops; P toggles pause; Enter restarts after game over. On-screen left/right buttons move and repeat while held, down enables soft drop while held, rotate rotates once, and drop hard-drops. Tapping an empty area of the active game rotates the piece. Pause should stop gameplay and show a translucent dark overlay with a centered rounded dialog reading "PAUSED", "Tap pause to resume", and a RESET button. Game over should stop gameplay and show the same style overlay reading "GAME OVER", "Tap restart or press Enter", and a RESTART button. Include looping background music and short interface/drop/clear/game-over sound effects when audio is available after user interaction.