The initial Munchkin Kill-O-Meter includes one card for the standard Munchkin card game and one card for use in Munchkin Quest.
Munchkin Zombies Kill-O-Meter includes two cards themed for Munchkin Zombies, while also being usable in any Munchkin game.
Munchkin Cthulhu Kill-O-Meter, as you might guess, includes two cards themed for Munchkin Cthulhu.
Munchkin Apocalypse Kill-O-Meter includes eighty-seven, I mean, two cards themed for Munchkin Apocalypse.
Munchkin Steampunk Kill-O-Meter comes packaged with, yes, two cards themed for Munchkin Steampunk.