You think that Mr. Cat has ended his life? Not yet, evil's up again and this time he's back as Justice Mustache's pet, help him and his adventures of destroying 14 random enemies you'll encounter in their arenas, destroy all them and reveal the identity of a evil who's controlling evil.
There's also the infamous pirater Yong Yong.

Here's a 5-boss demo of the sequel to Mr. Cat, After you beat all bosses, nothing happens, just wait for the full version.
The 5 bosses are:
- NEDM Cat
- John Egbert
- Nyan Cat
- Hacker Magazine Guy
- Mergamehn

Some of the music is from Rockman & Forte: Challenger from the Future.