First LeapPhysics prototype

Every level in all seven worlds loads through the same recovered pipeline as First Leap, with each world's backdrop, music, particle effects and objects. Nails puncture the tyre, springboards launch, boost tunnels and bumpers push, cloud blocks crumble and coin piles pay 1,000 coins, all from the decompiled classes; flippers follow the buttons, crates, balls and barrels float, rope bridges hinge, the big Festival ball squashes as a soft body, and the original sounds and each backdrop's music play (the engine's pitch input is approximate). This is a playable physics reference, with recovered terrain, wheel motor, tap boosts, cage suspension, coin collection and water detection. The jungle backdrop scrolls in five layers. The player, bombs, wooden platforms, barrels, crates, coins, ground, water, cage and captive use recovered artwork. Other pickups and suspension links remain diagnostic; captive animation is unfinished. The tire follows the physical wheel angle. The rider turns, leans with travel and changes expression at the cage and in water. Contact-dependent lean is approximate. Coins and water animate on the gameplay clock and stop while paused.

Bombs ignite on impact, trigger nearby bombs and push exposed bodies. The rocket pickup carries the rider and steers with left/right. Boxes have no buoyancy. Characters and upgrades apply their recovered physics factors; Santa, Super spring and Auto boost effects are unknown and change nothing yet. All 16 characters, 9 engines and 15 wheels use their recovered sprite sheets and animations; engines and wheels are artwork only. Idle animations follow the recovered timer: after 4 s without steering, a 20% chance each time. The stuck escape (a kick along the summed contact normals after 0.3 s at a standstill while steering) follows Object396; some player states, camera behavior, sounds and captive animations are unfinished. The cage release runs on the fixed clock rather than the original presentation clock. Planck is a substitute for the unidentified original Box2D version; no original-device trajectory comparison has been made.

The game opens on the rebuilt welcome screen: the world's StartScreen level drives itself behind the logo, looping back to its start, and Play opens the world map. The gear opens the rebuilt settings (Sound works). Pausing a level shows the original pause screen: resume, back to the level list, or skip to the next level. VS. Friends and the World Cup are rebuilt over our own lightweight server (server/boom-server.mjs, part of npm run dev and runnable alone for hosting; the original's servers are gone): weekly World Cup rounds with standings, ghosts to race and prizes, and turn-based challenges against other players on the server by nickname, share code or random match, with the original's retries and 50-coin round wins. Without a server the screens show sample placeholders. The coin bar's "+" opens the get-coins dialog, where the packs are free gifts that say thank you instead of a price. Game Center and the other settings did nothing we can restore. Picking any level below still loads it directly.

Levels (or Esc, or the finish screen's menu button) opens the rebuilt level select: the scrolling world map and each world's level list, with the medals, best times and super stars saved in this browser. Tap a level to play it. The character button opens the rebuilt store: spin the rider, engine and wheel reels, buy the parts you don't own with the coins banked at each finish, and close it to wear an owned outfit. Friends, World Cup, buying coins, the not-enough-coins dialog and level and world locks are not rebuilt.

Ghosts. Every run is recorded in the original ghost file format (TrialSession's ghost log: position, wheel angle, hub rotation, facing and clip each update); a record keeps it as the level's ghost in this browser's IndexedDB, and from then on every run races it (the original waited for its ten-medal "ghost" reward) as a two-thirds-opacity rider in the recorded outfit, the name "Your record" fading in over it the first three times. The seven Boost and Rocket Race levels run the game's bundled Easy, Medium and Hard ghosts in their Stig outfits, chosen by the medals already won, with their names over them. The unlock reward dialog is not rebuilt.

The first left/right input starts the world and timer. The provisional speed meter displays total linear speed in physics units/s with a 0–20 bar scale; this is not a recovered original HUD formula. Simulation: 60 Hz, 8 velocity / 3 position iterations, legacy half-step accumulator. Long frames are capped at 100 ms; switching away pauses the game. Input trace ticks are local to the current restart.