Sonic Physics Prototype

Summary

• Recreated the core physics and movement systems from the classic 2D Sonic games in Unity.

• Engineered a custom kinematic character controller without using Unity's built-in Rigidbody2D physics.

• Implemented authentic momentum-based mechanics including acceleration, deceleration, rolling, and slope physics.

• Developed a multi-sensor collision detection system for precise terrain interaction.

• Designed a modular, extensible architecture to support rapid prototyping and future gameplay features.

• Researched and translated the original Genesis-era Sonic physics algorithms into modern C# implementations.

Tools Used:

• Unity 6

• C#

• Visual Studio

• Git

• GitHub

• GitHub Projects

Core Systems:

• Custom kinematic character controller

• Multi-sensor collision detection system

• Slope-aware movement and terrain handling

• Momentum-based acceleration and deceleration

• Rolling and ground adhesion mechanics

• Deterministic fixed-timestep movement

Technical Features:

• Pixel-to-world unit conversion system

• SpriteShape and EdgeCollider2D terrain support

• Modular player state architecture

• Custom collision resolution without Rigidbody2D

• Physics behavior based on the original Sonic Retro Physics Guide