This is a hack of the JP version of Megaman 2, called Rockman 2 - Dr. Wily no Nazo. It changes the level layout and graphics. Also changed is the music, which even includes some tracks from Double Dragon NES. Also included is other patches: Wild Version and Wild Version Boss Only. These alter the game further.
Rockman 2 - Dr. Wily no Nazo (J) [!].nes - GOODNES 3.14
CRC32: 30B91650
MD5: 055FB8DC626FB1FBADC0A193010A3E3F
SHA-1: FB51875D1FF4B0DEEE97E967E6434FF514F3C2F2
SHA-256: DEB88223311ACA8CA566B99D4063CA29D389D939FEE455F83AFAEC97C6F0A5D1