Some of it is crazy neat, like being able to rewind the mistakes you just made, and playing through them. The arcade coin-op machines are lovely; Tempest's sent me down nostalgia lane.
I tried to buy a game through the store, and it didn't register. Mashing on "BUY" "BUY" "BUY" but no effect. No XBL Purchase blade, no sound effect, nothing. Not sure what I'm doing wrong.