1. What Android version (ROM) do you use?
2. What kernel?
3. What game doesn't work?
4. Is this the case with all the games or just a few?
5. By videos, do you mean gallery videos or internet videos?
6. Is this the case with all videos or is the problem intermittent?
You have to give away more details for people to help you, man.
Device: Sony Ericsson Xperia X8
ROM: FroyoPro v2.5
Kernel: Stock (11w41)
Clock: 245/729 MHz, Smartass