allowing to customize its PCB specifically for the needs of FPGA console emulation.
From what I can recall, this is not what happened. He has stated multiple times that he’s designed it to work as much like a DE-10 Nano as possible. There are no significant differences between his board and the original from what I can tell.
Just Mario 64. However there is a very good implementation of the N64 in the Mister FPGA project. The downside is there aren’t many emulation features that you’d expect out of a software emulator (e.g. save states)