Kivi's Underworld occupies a very specific place in the annals of action RPGs. It's about as casual as these games can get without being utterly mindless. And I intend that as a compliment. Kivi's Underworld is perfect for ten-minute adventures where you don't have to re-remember what your skills do, or how your gear is set up, or which areas you need to play. It's based on short adventures in which you try to get high scores and unlock new characters. The action is simple and gratifying. Take your character into a dungeon, use his single special ability, kill monsters, and take the loot. If this game was on one of the console systems, it would be the perfect couch action RPG.

Kivi's Underworld was created by Soldak Entertainment, which is basically Stephen Peeler, the guy who made a really good action RPG with a twist called Pools of Danger Depths of Peril (review here). And he's just released a multiplayer add-on for Kivi's Underworld. It's basically a co-op patch that lets multiple players go through a dungeon together, scaling the difficulty by the number of players. Unfortunately, it's a $10 co-op patch. And while I can understand a small game-maker can't just release his work for free, it's going to be a tough sell on top of an already $20 game.

Of course, this raises the prospect of a multiplayer patch for Depths of Peril, a much more complicated action RPG that lends itself to direct head-to-head competitive play. Because that's ten bucks that's been burning a hole in my pocket for a while.