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 responsive 2D side-scrolling endless-runner-style platform game titled “Pulse Runner,” rendered on a full-screen HTML canvas with a fixed HUD layered over it. The camera follows the player horizontally: the player begins around 150 px from the left and the world scrolls once the player advances, with the player kept near 28% of the screen width. Use a neon cyberpunk visual style: a vertical dark navy-to-purple gradient sky (#101044 to #221038), a translucent blue-purple city skyline of rectangular buildings with tiny cyan windows, and a dark navy ground/lower area. Add subtle perspective/grid lines below the horizon, and draw a bright cyan glowing horizontal ground edge. Use canvas glow/shadow effects throughout.

The player is a simple luminous cyan square robot/avatar, 42x42 px, with a strong cyan glow. It has two dark square eyes and a short dark horizontal mouth, and rotates slowly while grounded and more noticeably while airborne. The player automatically runs to the right at a constant 360 pixels per second; there is no left/right movement control. Apply gravity of about 2100 and a jump velocity of about -760. The only gameplay action is jump: pressing Space, ArrowUp, or W, or tapping/clicking the canvas, makes the avatar jump. Support a short jump buffer (about 0.12 seconds) so a jump input just before landing is accepted. The avatar can land on the regular ground and on top of purple blocks.

Build a deterministic level approximately 8600 pixels long. Start the hazards around x=440 and lay out 42 repeating obstacle groups, with each group spaced by 190 pixels plus a 0/28/56 pixel variation. Include these obstacle patterns in sequence: one pink neon triangular spike; two adjacent spikes; one purple block (42 wide, 48 high); a spike followed by a 72-pixel-wide gap; three spikes; a 42-wide, 74-high block followed by a spike 62 pixels later; a 92-pixel-wide gap; and a spike followed by a 42-wide, 55-high block 52 pixels later. Gaps remove the floor, so falling through one causes death. Spikes are pink glowing triangles about 32 wide and 32 high, with collision detection using a slightly inset hitbox. Blocks are glowing purple rectangles with a lighter inset outline; the player may land on their top surface, but colliding with their side kills the player. Ignore off-screen objects for performance. Place a green glowing finish marker near the end (at approximately levelLength minus 250): a vertical green post 120 px high with a green rectangular flag and the text “GO!” in dark lettering. Reaching beyond the level end wins.

Game states should be ready, playing, dead, and won. On initial load show the player at ground level, the skyline and hazards, and a centered instruction overlay reading “TAP OR PRESS SPACE” with smaller text “Jump over the neon hazards.” The first jump/tap starts the run and hides the hint. While playing, display distance as whole meters, calculated as floor((player x - 150) / 10), never below zero. On collision or falling below the screen, stop movement, save the best distance in localStorage, and show a centered “CRASHED” message with “Distance [number] m · Best [number] m,” plus a visible bottom-centered rounded RESTART button. On reaching the finish, show “LEVEL CLEAR” with “[number] m · Best [number] m” and the same restart button. Pressing jump after death/win or clicking RESTART resets and starts a new run; R resets and starts immediately.

HUD styling: fixed full-screen overlay with “PULSE RUNNER” at top-left in bold cyan uppercase and the distance at top-right in bold white. Use responsive font sizing, generous dark text shadows, and roughly 16–18 px top padding. Add a thin progress bar near the bottom with rounded ends and a translucent white track; fill it from left to right with a cyan-to-purple-to-pink gradient, based on distance relative to the 8600-pixel level. Put the RESTART button above the bar, styled with a cyan border, dark translucent background, white bold text, pill-shaped corners, and a pressed scale effect. Make the canvas touch-friendly with pointer input and prevent scrolling. Keep the entire presentation minimal, clean, and neon-glowing, with no weapons, enemies, collectibles, lives, or extra abilities beyond the single-button jump mechanic.