Many games work perfectly (as far as I can tell) but many games do not. I have suffered glitches and strange graphical craziness in the following games:

Castlevania AoS (Large creature models with multiple moving parts don't work properly causing disjointed shapes to move strangely about the screen.

Teenage Mutant Ninja Turtles (second level is totally glitches out)

Super Mario Advanced (the slot machine bonus doesn't have any pictures.)

If anyone else suffers from the same glitches I would love to know I am not the only one. But I am going to have to say to proceed with caution. I was probably 5 hours into Castlevania before I discovered the glitches. Now I am afraid to commit to any game.