A while back I was considering doing PikminDS. I couldn't get bullet down to a reasonable size, but I have managed to get reactphysics3d into a pretty small ammount of memory. I'm still working on getting the 3D APIs to work, so it's difficult to test how successful the port was, or whether it is working at all. So yeah I don't know if I'll get around to using it, but here it is. If you are considering doing a 3D project that needs physics you can get the library here. https://sourceforge.net/projects/libreact3dds/ Please not that the math backend has not been ported to use the vector fixed point hardware acceleration, and will attempt to perform all calculations using software emulated floating points if using ARM-THUMB, so use it sparingly.