The GameBaby is a two-part case which, when not in use, protects the sides and back of your iPhone from damage. However, you can detach the bottom section and turn it around so that its physical buttons rest on the screen.
Here's some PR:
The GameBaby is an iPhone 15 Pro Max & iPhone 16 Pro Max case with an added feature. In addition to providing protection for your phone, the lower part of the case also serves as a game controller. You can detach it from the back of your phone and place it on the front in order to play retro games with a physical interface similar to those of the controllers of 16-bit consoles from the early 90s. After finishing your game, the GameBaby returns to its original shape, protecting your iPhone and allowing you to enjoy its full screen.