Today, Indie-ana Co-Op goes on an adventure in the wide world of iPhone/iPad gaming. The common theme for this installment? Zombies. Two different takes on the theme are investigated: Tweet Defense and Alive 4-Ever Returns.

Did you know Co-Optimus now lists iPhone/iPad/iPod games in its database now?  It does.  Despite covering the platform for some time we just didn't feel it was worthwhile to break out the few co-op games it has, but now with several high profile releases, we've decided to track these titles more closely.