Rockman X4

Rockman X4 is a bootleg game from Makon Soft. It is a roughly colourised version of another Makon bootleg called Rockman 8: Metal Heroes, which is itself a bootleg Game Boy version of Mega Man 8.

Rockman X4 was made by Makon Soft in 2000 and is pretty much exactly like Rockman 8 with an attempt at colorization, but it has different intro pictures (This time showing scenes from Rockman X4) and a different stage select screen. Also, it doesn't show you a Rockman World 3 boss when you select a boss. Instead, it shows the boss' mugshot.

Source: TheGamesDB