Area 1 (US: Round 12)[edit]
This area contains: thirty-two Special Invaders (eight of each of the first four types), in a vertically-moving formation; it will become horizontally-moving when there are only eight invaders remaining, and you will also have to watch out for meteors falling down from the top of the screen during this world (which can be destroyed for 100 extra points apiece).
Area 2 (US: Round 13)[edit]
This area contains thirty-two Special Invaders (eight of each of the next four types), in a vertically-moving formation; it will occasionally rotate 90 degrees anticlockwise and will again become horizontally-moving when there are only eight invaders remaining. The song you will be hearing from the Yamaha YM-2610 is once again a brand-new composition.
Area 3 (US: Round 14)[edit]
This area (once again) contains thirty-two Special Invaders (eight of each of the first four types), in a vertically-moving formation; it will again become horizontally-moving, when there are only eight invaders remaining, and once you have cleared it, the boss theme will (again, if you are playing the US version), start to be heard from the Yamaha YM-2610.
Area 4 (US: Round 15)[edit]
As the (second, if you are playing the US version) Boss Invader comes down into view from the top of the screen, it will fire six missiles from its sides down at those CG30s, then drop its bottom part to fire "double-helix" lasers down at them (before it returns to it, like a boomerang); as it shall reveal its face at this point, this is the only time it is vulnerable, and once you have hit it five times it will change colour from blue to yellow (and again from yellow to red when you have hit it ten times). Once you have hit it fifteen times, it shall explode and fall off the bottom of the screen, and the player who registered the killer shot will (again, if you're playing the US version) receive 50000 points - the game will then go back to the zone selection screen, and you will have ten seconds to choose between World 3B and World 3C (but if you are playing the US version, you'll proceed to World 2C or "Round 16", the theme of which is identical to that for World 2A).