Physilinks

Physilinks is a browser-based physics linking game built with Matter.js. Match and chain same-colored falling balls; link enough to clear them and rack up points.

Play instructions

• Open index.html in a modern browser (desktop or mobile touch).
• Choose a scene from the selector (changes gravity, obstacles, spawn rate, palette, ball size). Switching scenes restarts the run.
• Click/touch a ball to start a chain; drag through balls of the same color to add them. Drag back to the previous ball to undo the last link.
• Release: if the chain length is below the minimum, links vanish; if it meets/exceeds the minimum, linked balls are cleared and you score 10 × length² (popup shows the gain).
• The top is open; if a new ball cannot enter because the entry is blocked, the run ends. The overlay shows final score with a restart button.
• Pause/resume with the button or Esc. HUD shows spawn rate, min link, chain length, score, per-scene high score, and palette legend.

Tech notes

• Engine: Matter.js (via CDN). Canvas rendering with custom overlays for HUD, pause, game over, and score popups.
• Scenes: Defined in main.js as an array of presets (config + createBodies factory). Applying a scene updates gravity, spawn rate, ball radius, palette, link constraints (stiffness/stretch/damping/width), and static bodies, then restarts the game.
• Physics entities: Falling balls (Bodies.circle) with gentle restitution/friction; static boundaries/obstacles per scene. The top is open; sides and floor are static bodies.
• Input: Pointer/touch events mapped to scene coords; chain state tracks bodies and a dashed preview line to the pointer. Undo by dragging back to the previous node.
• Scoring: 10 × length² per cleared chain. Score popup rendered as DOM element near release point.
• Persistence: Per-scene high score stored in localStorage under physilinks-highscore-<sceneId>; loaded on scene change; HUD shows current scene's best.
• Game loop: Single Matter runner started once. Pause sets engine.timing.timeScale = 0 and stops spawning; resume resets time scale and spawner. Game over stops spawner, freezes physics, and shows overlay.
• Lose detection: Spawned balls monitor entry; if they remain near the spawn zone with negligible velocity after a short delay, the run is over.

Development quick start

• No build step. Open index.html directly in the browser.
• Key files: index.html (layout), styles.css (styling), main.js (game logic).
• Adjust or add scenes in main.js by extending the scenes array with config and a createBodies(width, height) function.