Neon Coil

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 2D arcade snake game titled "Neon Coil". Render the playfield on a full-screen HTML canvas over a very dark navy/black background with a subtle radial gradient, and use a crisp neon cyberpunk visual style. The game board is a centered rectangular grid with approximately 20x20 cells depending on viewport size: thin dim blue-purple grid lines, a bright cyan glowing border, and enough bottom margin for touch controls. Adapt the cell size responsively between about 18 and 30 pixels, keeping at least 12 columns and rows and centering the board horizontally and vertically beneath the HUD.

At the top, display a fixed HUD with three evenly spaced rounded pill panels labeled SCORE, SPEED, and BEST in uppercase cyan glowing text; show the values in bold white. Start at Score 0, Speed 1.0x, and Best 0. Persist the best score locally between runs. In the center before play, show a large glowing magenta title "NEON COIL", the instruction text "Eat the sparks. Grow longer. The coil accelerates as you grow.", and a cyan-outlined dark button labeled "START RUN". Clicking it begins a new run and hides this message. When the player crashes, stop play and show a centered game-over message titled "COIL LOST", text in the form "Score [score]. Your coil reached [length] segments. Ready to push farther?", and a button labeled "RUN AGAIN".

Implement classic grid-based snake movement. On each new run, initialize a three-segment coil in the center of the board, traveling right. Draw the head as a small rounded glowing white square and the body as rounded squares with neon cyan-to-purple coloring along its length; every segment should have a soft colored glow. Place one glowing pulsing magenta circular spark/food pickup at a random unoccupied grid cell. The snake advances automatically on a timed step, initially about every 0.145 seconds. Eating the spark increments the score, grows the snake by retaining the added segment, emits a brief burst of around 16 small magenta particles, and places another spark in a free cell. Increase movement speed as the score rises using a multiplier of 1 + min(2.2, score * 0.055), and show that multiplier rounded to one decimal place in the SPEED HUD, reaching a maximum of 3.2x. Add a small screen shake on pickup and a stronger shake on collision, fading the shake quickly.

The run ends if the next head cell goes outside the board or intersects any existing body segment. Do not allow an immediate 180-degree reversal: reject a requested direction that is directly opposite the current direction. Support keyboard Arrow keys and WASD, the on-screen directional pad, and swipe gestures on the canvas (horizontal or vertical swipes choose the dominant direction). While running, show a four-button touch D-pad near the bottom center in a 3-column by 2-row arrangement: up centered above left/down/right, with cyan translucent rounded borders and arrow glyphs. Make it slightly faded on larger screens but fully usable on touch devices. The canvas should prevent touch scrolling. Space should start a run when not running.

Use rounded cyan-bordered buttons and translucent dark blue fills throughout the UI, with cyan/magenta glow, white bold values, uppercase letter spacing, and a deep blue-violet nighttime palette. Keep the game entirely real-time, interactive, and playable, with no enemies, weapons, lives, or additional power-ups beyond the single magenta spark food and the snake’s wall/body collision rules.