I architected and implemented the scene/entity system.
Architected and implemented 3d model/shader/texture/animation and audio content pipelines.
Architected and implemented the level, character composition, particle and audio editors.
Architected and implemented the graphics and audio systems.
Architected and implemented the build system.
Architected and implemented the Collada based physics asset pipeline.
Integrated the Bullet Physics System into the Engine.
Multithreaded the engine.
All of that for 3 platforms (whew…)