I gave Zombie Carnaval a look because its developer, Mobigame, has earned my trust with puzzle offerings like Cross Fingers, platformers like Perfect Cell, and EDGE, one of my favorite mobile games of all time. On its own, the premise of Zombie Carnaval would seem to be derivative. But a mechanism that adds slobbering, staggering shamblers to your horde keeps you invested in choosing your jumps and prolonging their rampage.
For example, the one zombie you start with is not enough to shove away automobile blocking your path. Now, chomp down on two or three hapless civilians, and you'll add two or three bug-eyed undead monsters to your pack, and now they can push aside and flip over cars. Just remember to jump at the right time, because they'll trail you, the leader, and can fall into a pit even if you keep going.
Like Jetpack Joyride, there are goofball transformations—my horde turned into a giant Chinese New Year's dragon, and also an enormous, bulbous, multiheaded ... thing that shot death rays at cars, bombs and other obstacles in its path. The purpose is the same in both games—just keep running as long as you can, rack up coins on the screen, and see what happens when you open the mystery box.
It's a one-touch game, of course, with the touch being the jump (or, if you open the "balloon" modification, sinking to the ground) Treat yourself to powerups and other boosts with a trip to the unlockables shop; yes, you can buy up currency to get what you really want if you don't feel like putting in the time.
If it was any other shop I wouldn't give the concept much of a chance but Mobigame's credit is good with me, thanks to its previous, well thought-out successes. The tail-growing variation, manifested as the gang of undead trailing you, is novel for this type of game, with some clever applications. The game is, of course, only $0.99 and if you haven't introduced yourself to an endless runner yet, this is as good a place as any to start.
Zombie Carnaval [iTunes, $0.99]