How,can,I,back,up,games,on,Phone,5's,without,losing,my,data?

How do I transfer game apps from iPhone 5s (iOS 10.2.1) to an iPhone 7 Plus (iOS 10.3.1) without losing my data? I'd like to continue play the games where I left off and not start over. I backed up the 5s in iCloud. The iPhone 7 Plus has been set up. I don't know how/where to get the games though.

Thank you for your time.