Here is a full level hack for Mega Man 4.
Mega Man 4 (USA) (Rev A).nes - NOINTRO
CRC32: 9ED9D3AF
MD5: 1A4FDAECE6AE32E5878029DA63866D94
SHA-1: 0FA8D2DADFB6E1DD9DE737A02CE0BFA1CD5FF65D
SHA-256: 49227BD63E49B40DCB4F44DBC2A6EEA27EC9E27ACDFCEFFBD856ADFE8E55CFA9