Sometimes, a game comes along that is so bizarre, so weird, so completely out there that it's difficult to describe just how strange it is. This isn't one of them. In this game, a unicorn teaches you how to use farts to kill zombies. Duh. Of course some walkers only react to certain types of flatulence. Everyone knows this. That's why we have unicorn trainers.
The gameplay is very similar to the Plants Vs. Zombies that you were totally thinking about when you read the name of the game. Food comes down the line, you eat it, and colored gasses come out of your posterior.