I think mini projectors are good for gaming if you don't have the space for a TV or bigger computer monitor. But, I think the picture quality, and video resolution is not as good as a TV or PC monitor.
Mini projectors are probably best for mobile gaming since both smartphones, and mini projectors are small and easy to carry around.
I agree the pictures are not as crisp. I think the main reason for the less crisp picture is because of the lower resolution on the cheaper projector models, and people don't know how to properly focus the screen.
A lot of people also don't buy a proper projector screen like movie theater screens.
HD projectors are still pretty cheap in comparison to a plasma Television. I say that maybe you shouldn't go with the mini projector so much unless you are thinking about strictly playing games on a smaller device. In that case it is a perfect match simply because the size does allow you to plug up and play on a wall anywhere that is dark enough for you to see. It all boils down to what you are willing to sacrifice.
