Knightfall: Death and Taxes - Namco is pretty good about trying to fudge genres together -- which makes Knightfall right up their alley. Nightfall is an RPG puzzler with a whopping 100 levels. The game features special abilities, different fighting styles, and a strange puzzle system that requires you to rotate levels to beat the puzzles. It's hard to really tell what the game is like, as the promo video is quite obscure.
BIT.TRIP BEAT - BIT.TRIP BEAT comes from the popular WiiWare title of the same name. The game resembles a musical version of Pong, where you have to bounce off wave after wave of balls to the beat of the music. the game includes the original three levels that came with the Wii version as well as additional levels that are able to be bought via in-app purchase for $1.99. There's no word on the multiplayer yet but the WiiWare version has a 4 player coop mode which would be supremely cool.
More Brain Exercise - More Brain Exercise looks like the iPhone's answer to Big Brain Academy on the DS. In it, just like other games in the genre, you complete a multitude of simple brain exercises to determine your braing age. As you play more and more of the game, your brain age will undoubtedly get younger over time. It comes complete with a hot-seat multiplayer mode and Facebook integration, so feel free to try to prove your intelligence to all of your friends.