I think we need a little more info than just that to help you find a solution. Which base module are you using? Have you been following one of the tutorials, and if so, which tutorial dit you follow, and did you follow it to the letter or did you divert from it at any point? At which point in the code does the game freeze up, ie which part of the script is being executed erroneously? What happens when the game freezes: does the screen glitch out, turn green or are all game assets frozen in place, and does the music (if any) keep on playing or does that freeze as well?