Tiny Platformer: Minimalist 2D Browser Jump Game (Playable Reference Engine)

Tiny Platformer is an open-source 2D side-scrolling reference game designed to demonstrate swept collision detection, momentum physics, and deterministic fixed timesteps in lightweight HTML5 canvas. Authored by Jake Gordon under the MIT licence, this project strips away commercial bloat to present a concise, readable masterclass in foundational 2D platformer architecture that executes in milliseconds inside any modern web browser.

Physical Engine Constants & Architecture Specifications

Platformer engines live or die by the precision of their collision resolution and timestep loops:

Engine Constant	Value	Technical Role
Physics Timestep (dt)	1/60s (16.6ms)	Fixed delta prevents tunneling regardless of display refresh rate
Tile Resolution	16 x 16 pixels	Scaled cleanly across 512x384 to 1024x768 viewports
Max Horizontal Velocity	120 pixels / sec	Reached via smooth acceleration curve
Jump Impulse Velocity	240 pixels / sec	Delivers consistent, readable arc heights
Gravity Constant	600 pixels / sec²	Provides crisp downward acceleration without floatiness

Engine Deep-Dive: Swept Axis-Aligned Bounding Box (AABB)

The primary reason amateur platformers feel sluggish or suffer from “wall glitching” is naive collision detection. Tiny Platformer demonstrates how to handle fast-moving player collisions cleanly:

1. Swept Collision Projections: Instead of checking overlap after the character has already moved, the engine calculates the projected bounding box between frame T and T + dt.
2. Axis Decoupling: X-axis movement and Y-axis movement are resolved independently. This ensures that wall collisions do not arrest downward vertical falling momentum.
3. Momentum Preservation: Running jumps carry horizontal speed forward, rewarding deliberate player pacing.

Modifying & Extending the Map

The game level is decoupled from the rendering loop and stored in level.json. Developers and tinkerers can modify map geometry using any standard text editor or the open-source Tiled map editor without recompiling binary assets.

Open-Source Transparency

Served directly from local static assets via the canonical Jake Gordon javascript-tiny-platformer repository. Zero third-party tracker scripts, zero cookies, and complete client-side execution.