There's a number of reasons why this game has just charmed the pants off me (not that I was wearing pants to begin with). The first is the art style, which is charming, but lots of games have charming art styles. It's the art combined with some really slick co-op style platforming mechanics. Think of it as a 2D version of co-op portal with some Mario Galaxy schizophrenic platforming mixed in.
It's being released on the PSN this year, with a PC release coming afterwards.