It is a known fact that the original release of Mega Man III on the NES was largely incomplete. Between 2012 and 2015, a rom hacker by the name of "Kuja Killer" released an updated version of Mega Man 3 that fixed many bugs, reduced lag and added several new features but left all the level design intact.
The purpose of this hack is to build upon what Kuja Killer has done and re-balance the game's level design. The Doc Robot stages were originally very difficult and frustrating with Wily's castle being laughably easy. These two sections of the game have been altered for a more logical difficulty curve.
This is how Mega Man III should have been back in 1990.1
Version 1.1 update
Mega Man 3 (USA).nes - NOINTRO
CRC32: 452D8089
MD5: 75B924155CAFEE335C9EA7A01BFC8EFB
SHA-1: 53197445E137E47A73FD4876B87E288ED0FED5C6
SHA-256: EDDBE571CF0A201BA9D090FBACE9843C9C9DD4053051649F2575B088752F4675