Marble Arena

From the archived website:

Zap your way to the top in this new and exciting, free 3D game. Control your marble around easy to intricate full 3D levels, up and down slippery slopes, mastering physics contraptions such as air vents, jumppads and vortexes.

Fight your way through AI controlled marbles and send them flying into each other and towards their doom. The more points you get the bigger you grow and the harder you are to be pushed around by physics mechanisms or other marbles.