Pulse Runner

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 polished 2D canvas endless runner titled “Pulse Runner,” using a full-screen responsive layout with a dark futuristic neon aesthetic. The game is viewed from a fixed side-on perspective: the player stays near the left side of the screen while the ground, obstacles, collectibles, and background grid scroll from right to left. Use a deep navy vertical-gradient sky, from approximately #0c1231 at the top to #07101f near the bottom, with about 80 small softly twinkling pale-blue stars in the upper 72% of the screen. The lower 22% is a dark blue ground platform, separated from the sky by a thin glowing periwinkle-blue line; add repeating short cyan dash marks along the ground and faint diagonal perspective/grid lines in the sky. Make the visuals glow subtly with neon shadows and keep the style clean, geometric, and arcade-like.

The player is a glowing cyan square, about 30 pixels wide, positioned at roughly 19% of the viewport width and standing on the ground. It has a dark navy inset square in its center, with a tiny white square detail and a small yellow square detail, creating a simple futuristic robot/core appearance. The square rotates in 90-degree-like increments while airborne and settles upright on landing, with cyan glow. The only gameplay action is jumping: Space, Arrow Up, W, or tapping/clicking anywhere on the canvas makes the player jump if grounded. Apply strong gravity and a single jump impulse so the player must time jumps over hazards; do not allow double-jumping. Add a small cyan particle burst on jump and landing.

Make it an endless automatically advancing run. Begin at a horizontal movement speed of about 360 pixels per second and continuously increase speed over time (approximately 5.2 pixels per second squared), causing the tempo/difficulty to rise. Spawn hazards from the right edge at roughly 1.05–1.42 second intervals, with the interval becoming somewhat shorter as speed rises but never below about 0.72 seconds. Most hazards are single neon pink triangular spikes, with approximately 25% being double-spike formations: filled glowing pink triangles sitting on the ground, with each triangle about 42–68 pixels tall (double formations use two roughly 52-pixel spikes separated by a small gap). Collision with a spike ends the run. Use a slightly forgiving collision box so the player’s square must substantially overlap a spike before dying.

Sometimes, when spawning an obstacle, also spawn one collectible golden-yellow diamond-shaped spark farther ahead, approximately 170–280 pixels beyond the obstacle and 70–125 pixels above the ground. The spark slowly spins and glows. If the player’s square touches it, remove it, award 50 points, and emit a yellow particle burst. Passing an obstacle completely off the left edge awards 10 points. Display the score as a four-character zero-padded number in bright cyan at the top-right; display “PULSE RUNNER” in uppercase pale blue at the top-left. Persist the best score locally between sessions, and show it in the run-over message.

The idle/start screen should retain the animated starfield and background, with a centered rounded rectangular glassy navy card approximately 420px wide maximum. The card has a subtle translucent blue border, inner blue glow, and shadow. Show the large uppercase title “PULSE RUNNER” in white, widely letter-spaced type, followed by the exact or equivalent description: “Dash through the beat. Jump the spikes, collect sparks, and survive as the tempo rises.” Include a large rounded button labeled “START RUN” with a cyan-to-blue gradient, dark text, and a soft glow. Under it show: “Keyboard: Space or ↑ • Mobile: tap anywhere”. At the bottom center of the viewport show the instruction “SPACE / TAP TO JUMP” in small muted blue text. Starting can happen through the button or by pressing the jump control; hide the card during play.

When the player hits an obstacle, stop gameplay, keep the scene visible, and show the centered overlay card again with the heading “RUN OVER,” text such as “Score [score] • Best [best]. The pulse gets faster every minute — try again.” and a button labeled “RUN AGAIN.” Reset the player, obstacles, sparks, particles, score, speed, and run state when restarting. Animate the world continuously even while idle with a subtle pulse rhythm affecting star brightness and grid/line opacity, and use square particle fragments in cyan, blue, yellow, and pink for jumps, landings, collection, and game-over effects. Ensure the interface is touch-friendly, prevents page scrolling, fills the viewport on desktop and mobile, and adapts the player’s ground position to the viewport height.