A great way to enhace image quality for some games is rendering them in higher resolution than the native display resolution:
For example, the anti-aliasing of "The Great Ace Attorney" is pretty poor.
Game rendered in native 1280x720 with AA:
Game rendered in 2560x1440 with AA and downsampled to 1280x720:
Almost no impact on performance or battery life, since this game runs on a potato.