Is it all games or one game? Do they all crash or are they just glitchy? Without knowing which game(s) I would say that the place to start is with what is running on the device. Look at your running apps list which is usually under "apps" on your main menu or options screen. I would also check under memory and see what is using your resources. There are apps on the market to make monitoring this a bit easier. Search for "resources" or "memory monitor". In the meantime the two other things I would try are; Power the device off and back on, don't do a restart fully power the device down and back on, then immediately open one of the problem games and see if it performs better. Alternately turn fastboot off and do this same thing. If they work ok at start up it may be a background app that is gumming up the works. The other thing I would do if it's one or two games would be to contact the dev. of the game and see if they have any suggestions or advice. Chances are if there is a compatibility issue they've already heard about it or may have a list of apps that don't play nice with your game. Usually if you get an app from Google Play it will only show you apps that are compatible with your device, however if you are getting games from other locations or bringing them from an old device there could be a compatibility issue.