Honestly if you're having registry errors, uninstall the game and reinstall it. If the program is worth anything it will clean the registry before it completely uninstalls.
Sometimes programs do not clean the registry and leave tidbits behind. In most cases these do not slow down your performance until you get a TON of them, even then it doesn't affect performance THAT much. At the same time registry cleaners (not picking on one type, just saying in general) have the potential to do irreversible harm and cause your whole operating system to become unstable.
In my opinion as a PC Technician by trade, if your registry is so cluttered that you feel you need a cleaner for it, it is probably long-past the time for you to do a backup and full reinstall of Windows. I generally recommend people do a clean install every 1-2 years depending on how often you install new programs. By getting a clean start and only reinstalling the programs you actually use, your system will run cleaner and you will also have the benefit of not having possibly insecure software installed on your machine (that you no longer use).