This is Portabliss, a column about downloadable games that can be played on the go. Plants vs. Zombies has long been one of the most popular titles on the App Store (or any platform it's been released on, really), but PopCap has only recently revealed a sequel set to arrive in another month or so. In all that time, then, it's not surprising that game developers have "borrowed" PopCap's casual tower defense formula, where you build up units in lanes to defend against an oncoming horde. Samurai Bloodshow is one of the best pretenders to the throne, and there are other games like Legendary Wars that took PopCap's premise and ran far with it.

Evilot also belongs in the second category. It's a recently released iPad game that has a very clear resemblance to the longtime battle of flowers against the undead, in that enemy troops come in by lanes from the right, and you need to build up units to defend treasure on the left. But while Plants vs. Zombies uses a straightforward currency system to build up its units, Evilot borrows a core mechanic from another great iOS title: Triple Town.