Gameboy frontdide 
Gameboy borderside 
Gameboy rearside
How to build
In this video, you can see the final result. The project was made by GreatScollLab and is available on instructables.com website.
I have buy all necessary staff on Aliexpress:
- 3.5 Inch TFT LCD display
- PCB controller card common ground for Raspberry Pi Nintendo Game Boy
- Gameboy Console Shell Case
- Mini PAM8403 3w stereo amplifier module
- Raspberry Pi Zero W (wifi and bluetooth 1 GHz CPU 512 Mbyte Ram)
- little speaker 8 ohm
- wires