It is normal that the CPU usage is higher when you play games, however it shouldn't reach 100%. If it does, consider uninstalling the game from your computer because you might damage the CPU if you overload it too much.
Systemrequirementslab is a good website which can tell you whether your computer can run a particular game or not.
If your computer can't run a particular game, consider upgrading your computer, or even buying a new one (if it's impossible to upgrade the already existing one).
Check out the don't know which computer to buy guide, if you don't know which one to select.
If you don’t receive the email in the next 2 minutes please check your junk folder, and add [email protected] to your safe sender list.