Those games must be compatible with your iPhone. If they're .IPA files, then you can install them by transferring the games to your PC and using iTunes.
Before installing, please make sure you've downloaded those games from trusted sources. You could expose your iPhone to security issues otherwise.
To get started, connect your iPhone to your PC using the lightning cable and open iTunes. Your iPhone will appear in the left pane under "Devices". Locate your .IPA files on your PC, then drag and drop to your iPhone's name in the left pane so that your apps will begin to install.
Alternatively, you may find those games directly on the App Store. The steps above will then not be necessary.
Hope this helps.