a Nintendo Gameboy emulator is easy and simple to install for TI Nspire calculators. Make sure to read the getting started section first.
1. First you need to have Ndless running on your TI Nspire calculator.You can download it from here!
2. The second thing you need to do is download the emulator from here.
3. And last you need some games a.k.a roms! You can get roms from various websites all over the internet. For example you could get this Pokemon Crystal game installed on your TI Nspire Calculator. Installation is simple, just put the rom into the same folder you have your emulator.