I ain’t a judge, but I suppose you can. As long as you keep to the limitations of the NES: Resolution, 4 colors per sprite (1 transparent), 8x8 sprites, grid backgrounds, you should be fine! The extension packs usually have hardware that offloads calculations from the NES CPU onto the cartridge. Then again, there are pseudo-3D games that you could simulate. One game that I really had fun with was Battle Tank:
