Area 1 (US: Round 20)[edit]
This area yet again contains twenty-two Large Invaders, twenty-two Medium Invaders and eleven Small Invaders in a horizontally-moving formation; but this time, when one is killed, the remainder of its column drops down to the bottom of the formation. The song you will hear from the Yamaha YM-2610 in this world is also identical to that for World 1A.
Area 2 (US: Round 21)[edit]
This area contains: fifty-five Special Invaders (five of each of Types 9 through 13), in a horizontally-moving formation; Type 9 look just like pairs of legs, Type 10 like shorts, Type 11 like jackets, Type 12 like heads and Type 13 like hats.
Area 3 (US: Round 22)[edit]
This area contains eleven (as opposed to 22) Large Invaders, thirty-three (again, as opposed to 22) Medium Invaders and eleven Small Invaders, in a horizontally-moving, wrap-around formation; once you clear it, you will proceed to the second "Cattle Mutilation". However, if you are playing the US version, you shall proceed to World 3B, or "Round 23".