It's presented like an anime in parts with episodes that include opening and ending credits and general anime stylings e.g. repeating the end of the previous episode final 10-20 seconds.
Not gonna lie, it is very short. I didn't time it and there's no in game clock from what I know but I'm sure it didn't clock up to even 5 hours (all inclusive).
Basically the game is also done in a way that, yes it's short, but it's also extremely easy to just drop in and out of if you really haven't got that much time to dedicate. If you want something long and engrossing then you're better off with a solid RPG.
SSFIV: Guy, Fei-Long
Tekken 6: Miguel, Leo, Kazuya