Not able to play itouch games after failed Sync

hi friends my friend has a itouch ver 2.1, when i added songs and videos to it added perfectly but when i ready to install game downloaded from itunes it asked to sync, i agreed to that and pressed yes button but it started to remove all the applications in itouch and suddenly i cancel that, after this i removed it from usb. when i checked the games on itouch it doesn't starts, the problem is whenever i start the games it goes on to main screen and none of the games work. but all the music and videos are intact. i restarted the itouch but no use . please tell me the way i can retrieve the games. actually the memory shows all the applications present in it.

Topic Moved to appropriate Section.

You need to reinstall as they may look installed there but they are corrupted as part of them was removed already.