I'm kind of glad the Vita doesn't have an activity log like the 3DS, because I think I'd be slightly embarrassed by just how much time I've sunk in to this game... especially considering I have Uncharted, Rayman, BlazBlue, Mutant Blobs Attack and Escape Plan (and various PSP games to boot) almost all unplayed.
Also, I've said this in the Vita |OT| thread, but everyone, please I implore you all to add the Shatter OST onto your Vita's and have it playing in the LiveArea as you play this game. The BGM for this game is already great, but my based God above if the game doesn't get outright Godly when you have Shatter's music playing as you wreak shop.