Not to hijack this thread but 3D games are possible on calc. I have a few demos of my own that have a fair bit of stuff in them like basic AI and collisions etc:
Not sure if you can tell whats going on, but it just flying around shooting the objects. Only the xwing moves in the interactive demo, but thats just because the others are being told to stay still.
Aether3D was possibly the best engine performance wise, it could render complex objects at very good frame rates.
But ben is right, you need to be considerate with level design. Thats why i chose a spacesim since you dont need an environment beside some stars and planet sprites. Not saying that i will guarantee that ill finish, but i planned on having a max of 6 objects (like a broken freighter to protect, 1 wingman and waves of 3 enemies to destroy for example).