Complex sentence: Hagewood used his experience at Epic to found Psyonix, where among other contract projects they worked to try to find a way to make racing the "Unreal" vehicles in a physics-based engine enjoyable.
Split into simpler sentences: Hagewood used his experience at Epic to found Psyonix. Among other contract projects, Psyonix worked to try to find a way to make racing the "Unreal" vehicles in a physics-based engine enjoyable.