PixBounce: 7 Satisfying Physics Games Built with Base44

Role: Product Designer & Creative Developer Tools: Base44, Claude, JavaScript (Canvas + Web Audio), Cloudflare Pages Deliverable: A live Base44 app with 7 physics games that record 9:16 clips with sound Timeline: 2 days

"Satisfying" ball simulations are one of the most-watched short-video formats: one simple rule, a number that keeps doubling, a sound on every hit and a clear finish. PixBounce lets anyone make one in the browser, record it as a Reel-ready clip, and challenge followers to call the winner.

The physics engine is hand-built. Base44 runs everything around it: sign-in, data, the leaderboard and player profiles.

Clips had to look like real Reels: fill the 9:16 frame, one bold rule on screen, a close finish and sound on every hit.

Races had to be fair, or "call the winner" means nothing.

Base44's free plan gives 25 message credits a month (5 a day), so the build had to be planned prompt by prompt.

1. Study the format. I broke down reference Reels frame by frame (layout, pacing, on-screen text) and read their audio spectrograms: a tick on every hit, a boom when a bar breaks, a chord at the finish.

2. Build the engine. A canvas physics engine with a fixed time step and seeded runs, so the same link always replays the exact same race. Matchups are balanced by simulation: across 30 simulated races per matchup, each side wins about half the time and the loser usually finishes one bar short.

3. Build the app in Base44. A detailed spec prompt set up the app layer: Base44 sign-in, a RaceCall data entity, a Leaderboard with today's daily-race split and top callers, and a Profile page with the player's Instagram handle. The game and the app talk through postMessage: race results go to Base44, and the handle comes back and is stamped on every clip.

4. Make it post-ready. Recording exports a 1080×1920 MP4 with sound and stops by itself at the finish. A limiter keeps loud moments from clipping.

Race: ×2 power vs ×2 balls. Call the lane that breaks all 9 bars first.

Dig: one ball whose power doubles with every hit.

Escape the rings: break out of 15 spinning rings.

Melody: every bounce plays the next note of a public-domain tune. Guess the song.

Duplicate, Gap escape, Growing ball: classic ring simulations.

A live, public Base44 app where every race call is saved and ranked.

🔗 Play PixBounce

Base44 is strongest as the app layer. Sign-in, data and pages came from one spec, so the hand-built work could go into the part that makes a clip satisfying.

Plan prompts like a budget. With 5 credits a day, one complete spec beats ten small fixes.

Test before you trust. Simulating races caught a balance problem that a few manual plays would have missed.

Sound is half the format. The physics drives every note, so each clip sounds different.