Glowcoil

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 portrait-friendly, responsive 2D arcade snake game titled “Glowcoil.” Use a full-screen HTML canvas with a fixed HUD layered above it. The visual style is dark neon sci-fi: a deep black-purple radial-gradient background (#05030d through #1a1030), scattered softly twinkling pale stars, and cyan, violet, and hot-pink glow effects. At the top, show the cyan uppercase brand “GLOWCOIL” with wide letter spacing. On the right of the top bar, show two dark translucent rounded statistic pills with subtle borders and inset purple glow: “SCORE” above the current integer score, and “SPEED” above a multiplier such as “1.0x.”

The play area is a centered square 20-by-20 grid, sized responsively to fit the viewport beneath the top bar and above mobile controls. Give it a nearly black translucent purple fill, a soft violet outer glow, and thin low-contrast grid lines. Implement a classic grid-based snake/coil: start with a four-cell horizontal body at approximately grid positions (9,10), (8,10), (7,10), (6,10), moving right. The head is the first segment and should be visually distinct hot pink, while the rest of the body is violet/purple. Render each cell as a slightly inset rounded square with a gradient from bright highlight to its neon color and dark purple, plus colored bloom; the head should have the strongest glow and a white highlight. Place one pulsing cyan glowing circular spark at a random unoccupied grid cell.

The player moves one grid cell at a time. Support Arrow keys and WASD on desktop, and on touch devices support swipe gestures on the canvas plus a visible bottom-centered four-button D-pad with up, left, right, and down arrow buttons. Prevent immediate reversal into the opposite direction. Each movement advances the snake; eating the cyan spark inserts a new segment, increases score by one, spawns another spark at a random empty cell, emits a small cyan particle burst, and accelerates the movement. Start at a 145 ms step interval (speed 1.0x), reduce the interval by 3.2 ms per spark eaten, and clamp it at 55 ms; display speed as 145 divided by the current interval, formatted to one decimal followed by “x.”

The run ends when the head crosses any edge of the 20x20 board or collides with the snake’s body. On collision, stop movement, show a centered restart overlay, and emit a larger hot-pink particle burst at the head. The overlay should be a rounded translucent dark glass card with a fine light border, purple shadow, and subtle pink inset glow. On the initial screen, center the card over the board with the large glowing white title “GLOWCOIL,” the subtitle “Eat the sparks. Grow longer. The coil accelerates every time you feed.”, a bright pill-shaped cyan-to-pale-pink “Start Run” button, and the hint “Arrow keys / WASD · swipe on mobile.” When the run ends, replace the subtitle with wording like “You reached [score] sparks. The coil hit the wall — run it back?” and change the button to “Restart Run.” Pressing the button, Enter, or Space while inactive starts/resets a run.

Animate the canvas continuously: clear and redraw the radial background, softly vary star alpha over time, pulse the cyan spark, and update/fade tiny colored square particles produced when eating or crashing. Keep the HUD and overlay legible on both desktop and mobile, account for safe-area insets, and show the D-pad only for coarse-pointer/touch devices. Do not add lives, enemies, power-ups, wrapping, or other mechanics; the only goal is to eat sparks and survive as long as possible while growing and accelerating.”,