Bit.Trip Fate is a 2D reincarnation of Rez. It's on-rails and you shoot enemies and objects to let them produce sounds, while collecting power-ups to keep yourself alive long enough to survive the boss fights. The worlds and main character aren't as detailed though, and Rez is still the better game between the two (play it if you ever get the chance!), but I'll be honest, Fate is not bad either. It's simple in its presentation, like all the other Bit.Trip games (ok, maybe not Runner 2) and they're never expensive. But, except for Runner 1 and 2, the games never manage to capture my attention long enough. I usually get bored of them within less than 2 hours.
That, and the fact that there are no checkpoints make it difficult to recommend this game. Sure, it's challenging, but it's too unbalanced. if you die during a level you have to replay the entire level all over again. It can be frustrating because you can usually make it to the boss fights without getting hit (too much).
Yup, the boss fights are tough. 'Aren't boss fights supposed to be tough ? And doesn't practice make perfect ?' Well, yes, but only if it's fun to play in the first place. Fate just isn't fun enough.