Gem Cascade

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 responsive, portrait/mobile-friendly 2D canvas match-3 puzzle game called “Gem Cascade” (the source page may be titled “Remix of a game”). Use a fixed full-screen dark interface: background #14161f, a top HUD with a dark blue-purple gradient, and an 8x8 square board centered in the remaining space. The board should resize to the largest square that fits with a small margin, and use alternating checkerboard cell backgrounds in deep navy-purple (#22243a and #1c1e30) with rounded outer corners.

Gameplay: start each new game with a randomly generated 8x8 board containing six tile types, avoiding any pre-existing horizontal or vertical run of three. Give the player exactly 25 moves. A move is made by swapping two orthogonally adjacent tiles. Support both touch/mouse swipe gestures (drag at least about 18 pixels in one cardinal direction) and tap-to-select then tap an adjacent tile; tapping the selected tile deselects it. Highlight the selected cell with a 3px pale-gold outline. Ignore input while animations are running or after game over.

A swap is valid only if it creates at least one horizontal or vertical run of three or more identical normal tiles, or if either swapped cell is a power tile. Invalid swaps animate outward and then reverse back without consuming a move; show a subtle translucent red circular invalid indicator during the reversal. Valid swaps consume one move and save a complete pre-move snapshot for Undo. Find every horizontal and vertical run of 3+, clear the union of all matched cells, score it, let tiles fall downward column by column, refill empty cells from the top with random normal tiles, and repeatedly resolve any new cascades until no matches remain. Animate swaps over about 150ms, clears over about 220ms by fading and shrinking tiles, and falling/refilling over about 260ms with eased motion.

Scoring must match these rules: each cleared cell is worth 10 points; each run contributes an additional 5 points for every tile beyond length three; multiply the total by the cascade level (first clear x1, next chain x2, etc.). Display a toast for chains of level 2+ such as “Chain x2! +N”. If a power tile is activated, also award 50 points per activated power tile and show “Power tile! +N” on the first-level activation.

When a horizontal run of length 4 or more is cleared, leave a row-clearing power tile in one of its cleared cells; when a vertical run of length 4 or more is cleared, leave a column-clearing power tile. Prefer a matched cell involved in the initiating swap when possible, otherwise use the middle cell of the run. If multiple runs select the same location, keep the first power assignment. Power tiles do not match by color. A power tile moved by the initiating swap activates immediately: a row power clears every cell in its row and a column power clears every cell in its column, combined with any ordinary matches. Do not recursively activate power tiles created or hit during later cascade steps; only the two initiating swap positions can directly activate a power tile.

Render six bright, flat geometric normal tiles, with no text or outlines: coral-pink circle (#ff5470), cyan-blue diamond (#3ec1ff), golden-yellow triangle (#ffd23f), mint-green hexagon (#38d996), purple five-point star (#b47eff), and orange square (#ff9f45). Shapes should be about 38% of a cell wide/high. The triangle points upward; the hexagon is regular-ish; the star has five points and deep inner points. Power tiles should be visually distinct from normal colored shapes: a pulsing pale-gold glow, dark navy circular gem body, pale-gold ring, and a bright cream horizontal bar for row-clearing or vertical bar for column-clearing.

After every resolution, detect whether any legal swap remains. If there are no legal moves, automatically generate a fresh non-matching board with at least one possible move and display the toast “No moves left — reshuffled!”. A power tile also counts as guaranteeing a possible move. Never leave the board stuck. When the move counter reaches zero, show a fixed dark translucent overlay with a centered dark blue-purple rounded panel, the heading “Game Over” in pale gold, “Final Score: N”, and a gold-orange “Play Again” button. Play Again resets the board, score, moves, selection, power tiles, and the one-use undo.

HUD: show “Score” and the current score, “Moves” and the remaining moves, plus a rounded “Undo” button. Use pale gray uppercase labels, large bold pale-gold values, and turn the moves value red when 5 or fewer remain. Undo is disabled until a valid move is completed, restores the board/score/moves from the immediately preceding valid move, can be used only once per game, and is disabled while animating or after game over. Resetting starts with Undo available only after the first valid move. Show toast messages near the top center of the board in a semitransparent black rounded capsule with pale-gold text, fading out automatically. Keep the visual style clean, flat, colorful, geometric, and minimal with no scenery, enemies, sound, or external assets.