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 browser canvas game titled “Pulse Runner,” an auto-running rhythm-platformer. Use a full-screen, non-scrolling canvas with a dark neon sci-fi aesthetic. The player is a small solid magenta/pink square with two dark square eye marks, positioned toward the left side of the screen; the world scrolls continuously from right to left while the player automatically runs forward. The only core action is jumping: press Space or Up Arrow, click/tap the canvas, or click the retry/next button. A jump is allowed only while grounded; give it a strong upward impulse, gravity, and a slight rotation while airborne, resetting rotation on landing. There is no manual horizontal movement and no shooting, enemies, health, or lives system.

Build five selectable levels. Each level is a finite auto-run course that ends when the scroll distance reaches 7000 + level*450 pixels. Start at level 1, with a level selector containing buttons 1 through 5. Completing levels 1–4 displays a centered “LEVEL N CLEAR” overlay and prompts the player to tap/press Space for the harder next level; completing level 5 displays “ALL LEVELS CLEAR” and a play-again option that returns to level 1. On collision, stop the game and show a centered “CRASHED” overlay with “Level N — tap, click, or press Space to retry.” Retrying increments the attempts counter. Track score as floor(scroll distance / 10), preserve a BEST score in local storage, and show a bottom progress bar filling according to course completion.

Generate obstacle courses procedurally per level beginning around x=600. Obstacles are grounded spikes and rectangular blocks. Use deterministic-looking spacing: the base gap tightens as level increases, and the course includes additional spike pairs from level 2 and occasional extra blocks from level 3 onward. Spikes are filled neon triangular hazards. Blocks are filled rectangular hazards with a small contrasting horizontal highlight near their top. Collision should use forgiving player hitbox padding. Blocks can be landed on from above, allowing the square to stand on their top, while their sides remain dangerous; spikes are dangerous on contact. Increase forward speed with level and gradually during the run, capped around 560, so later sections become more difficult.

Render a dark vertical gradient background, with each level using a distinct neon palette: deep indigo/magenta/cyan, purple/orange/yellow, teal/cyan/green, purple/pink/lavender, or brown/orange/red. Add subtle atmospheric glowing circles high in the background, diagonal perspective/grid streaks moving with the scroll, a dark blue ground strip covering the lower quarter, a bright palette-colored line along the ground edge, and repeating small pale dash marks on the ground. Keep the visual style clean, flat, geometric, and arcade-like rather than realistic; use subtle glassmorphism HUD cards with translucent navy backgrounds, thin pale-blue borders, rounded corners, and shadows.

Overlay HUD on top of the canvas. At the upper left show “PULSE RUNNER” in widely spaced bold cyan lettering and the subtitle “an original rhythm platformer.” At the upper right show LEVEL, SCORE, BEST, ATTEMPTS, and FPS values, plus compact “CAP 60” and “LEVELS” controls. The FPS cap control cycles through 30, 60, 120, and MAX and persists its setting in local storage; an FPS readout updates during play. The LEVELS control opens a right-side card titled “SELECT LEVEL” with five level buttons, and selecting one immediately starts that level. At the bottom center show the hint “Tap / click / Space to jump,” and at the bottom show a thin rounded progress bar with a magenta-to-cyan gradient fill. Make the layout responsive for narrow screens, hide the subtitle on small screens, prevent page scrolling/touch gestures, and support pointer/tap input as well as keyboard input. Include short square-wave beeps for jumping, crashing, and clearing a level.