It's just a graphics mod, with MOST character sprites edited, and Infinite lives.
(EDIT: Issue with character sprites not appearing correctly in Area 2 onwards FIXED)
(EDIT 2: FIXED issue where sprites reverted when fighting the door blocking mutant, now go forth blaster masters and MetaFighters!)
(EDIT 3) Andreia mode had been added: it just makes the metal attacker blue.
I have also added an optional patch where you can control the use of the "wall 1" powerup, by holding B.
Both optional Patches Should work on a vanilla copy of the game, and all patches work on all rom hacks of blaster master. they have been untested on Cho Wakusei Senki Metafight, however. When I Deem this romhack "Finished", I will port these upgrades to The Gameboy game "Blaster Master: Enemy Below".
Database match: Blaster Master (USA)
Database: No-Intro: Nintendo Entertainment System (v. 20210216-231042)
File SHA-1: ADB89B4923BB34805A39C141BAF227849A27CE41
File CRC32: 52BCF64A
ROM SHA-1: 98845D5716525E68EF7417E6FB55BE30A4C7130D
ROM CRC32: 3F0FD764