Blaster Master Zero | AREA 7 BOSS FIGHT!
Area 7 boss fight. Be careful after beating this boss not to travel back to earlier areas in the level because the elevator in the boss lair only works as a set-piece for the fight. If you do happen to go back to other parts of the level for items you may have missed, there's a warp gate that'll take you back to the end of the level to progress to area 8. However the backtrack isn't worth it otherwise.
