If you are looking for more gameplay that feels like the Zero series, the following are the best legitimate and fan-made alternatives:
: Another high-profile fan project. While the developers have experimented with test ROMs for the Game Boy Advance, they have stated that the final project will likely be a standalone PC/mobile application to avoid the technical limitations of the original GBA hardware. megaman zero 5 rom
: Available on modern platforms like Steam, Switch, and PS4. It includes all four Zero games and both ZX games with modern quality-of-life features. If you are looking for more gameplay that
: For fans of Zero’s gameplay in the X series, there are numerous ROM hacks for Mega Man X5 and X6 that rebalance the game and make Zero more viable or "canon-accurate". megaman zero 5 rom