It'd be nice to know what controls are...
Flip Flop Flag ALPHA
A downloadable game for Windows and macOS
Flip Flop Flag is a capture-the-flag style game where the players are totally unable to walk left or right, or even jump. They can, however, fall over.
Can you hold a flag by rotating left and right to defeat and defend from your opponent? Probably, considering your opponent can only do the same. Prepare for an adventure of falling over, falling down holes, floating away, falling off boats and generally failing in innumerable ways!
Go here (for a Windows computer) to learn how:
For a Mac: