I wonder if there could be a way to simulate lucid dreaming. :o
Telekinesis, flying, time warp and giant fireballs simulated by arm movements. There's not much else you need

Assuming the computer is really futuristic and powerful, it'd be exactly the same as real life except you can control everything.
Also, giant superpowered Gods deathmatch if it handles multiple people. "Life: Now in multiplayer!"