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 2D side-view endless auto-runner called “Pulse Runner” in a single full-screen responsive canvas, matching the provided visual style and mechanics exactly. The player is a small glowing cyan square, 34x34 pixels, positioned horizontally at about 22% of the viewport width (never closer than 90 px from the left edge), running automatically toward obstacles while the world scrolls left. The player has two small dark square eyes near the upper portion of its face, a cyan glow/shadow, and rotates while airborne. The floor is at 78% of the viewport height: draw a dark navy lower platform area, a bright cyan horizontal top edge about 4 px tall, and a subtle cyan translucent glow immediately below it. The player stands on this line.

Use a dark neon arcade aesthetic. Fill the background with a vertical gradient from approximately #11193b at the top to #090d1e at the bottom. Overlay a faint cyan perspective-free square grid: 48 px spacing in both directions, thin cyan lines at about 16% opacity, scrolling horizontally based on travel distance. The lower floor area is approximately #131c3a. Obstacles are glowing golden-yellow triangular spikes sitting on the floor. Normal spikes are about 34 px wide and 42 px high. Occasionally (20% probability), generate a double spike obstacle: visually draw two adjacent triangular peaks in hot pink (#ff5b8a), with an overall logical width of about 58 px and height 58 px; the second visible peak is offset to form a pair. Give obstacles a soft matching glow.

The game starts with a centered overlay modal over the scene. The overlay is a translucent very dark navy scrim. Its card is a rounded rectangle, approximately 360 px maximum width and 86vw on small screens, with a dark blue gradient, subtle white border, rounded corners, and shadow. Show the title “Pulse Runner”, the text “Jump the spikes. Stay on the beat.” and a cyan PLAY button. The top HUD remains visible: at the upper left, a rounded translucent pill reads “PULSE RUNNER”; at the upper right, another pill reads “SCORE 0” initially. Use bold uppercase Arial-like typography, with letter spacing. At the bottom center show “SPACE / TAP TO JUMP” in small semi-transparent white uppercase text.

On PLAY, begin an endless run and hide the overlay. Reset score and travel distance, clear effects and obstacles, place the player on the ground, and seed eight obstacles beginning around viewport width + 220 px, spaced about 210 px apart. The player automatically moves through the level while remaining at its fixed horizontal position. Base world speed is 360 px/sec and increases with score as 360 + min(score*3, 180), capped at 540 px/sec. Travel distance drives the grid motion and should increase by speed times delta time. Obstacles move left at this speed. As each obstacle fully passes the player, increment score by 1, update the HUD, and emit a brief golden particle burst. Keep spawning another obstacle whenever the final obstacle is less than about viewport width + 280 px ahead; place it roughly 190 to 310 px after the last obstacle. Remove obstacles once they are farther than 100 px off the left edge.

Jumping is the only gameplay action. Press Space, ArrowUp, or W, or tap/click the canvas, to jump. Only allow jumping while grounded. Set vertical velocity to about -760 px/sec, apply gravity of about 2050 px/sec², and land on the floor; do not allow double-jumps. While airborne, rotate the square at about 7.5 radians/sec. Emit a small cyan burst at takeoff and landing. Use forgiving inset collision boxes: inset the player by about 5 px on every side, and inset each obstacle by about 5 px horizontally and 6 px from its top; if the rectangles overlap, the player crashes. The triangular obstacle collision can use its configured rectangular bounds as in the source behavior.

When the player crashes, stop the run, retain the score, update a session best score, emit a larger hot-pink burst at the player, and show the overlay again with a card saying “CRASHED”, “Score: [score]” and “Best: [best]”, plus a “RETRY” button. Retry resets the run. Press Enter when not running should also start/restart. Render particles as small glowing colored square fragments with short fading lifetimes and gravity. Keep the canvas responsive to window resizing, cap device pixel ratio at 2, prevent page scrolling on touch, and make the game playable on desktop and mobile. Ensure the initial resting screen visibly matches the reference: dark gridded neon background, cyan square player on the cyan floor line, yellow spikes to the right, top title/score pills, and the bottom jump hint.