Here is a complete ROM hack for Rockman 4 which changes all the levels, music, and has graphical edits. Also some of the enemy behavior has been altered.
Rockman 4 - Aratanaru Yabou!! (Japan).nes - NOINTRO
CRC32: 771A9138
MD5: 8B4B65D68DEDC70A537505BDA430DAE9
SHA-1: C33C6FA5B0A5B010AF6B38CBD22252A595500A5A
SHA-256: AB4EB162A7BC84A317939B3F952314C9C7D0E6B7065210FF39322A3A13AEAA4C