Is there an error that pops up or anything? Device over heating? You'll most likely want to send a detailed report to support via email. Support@AThinkingApe.com Provide: Username Game you play(pimd) Your issue It also helps to send a crash report if your device gives you that option.
Do you have the most up to date version of pimd? Have you tried force closing the app from your task bar and re-opening? Is your device overheating? Do you have an old device? Are you using an android or iOS? If you have an up to date version of pimd, and your device is fine/not that old, then email support@athinkingape.com including your username, which game, and your issue with as much detail as possible, with screen shots if you can to help them work out the issue for you