it is deep but doesn't have the mini-goals like WOZ and TSPP do...for example, in Hobbit you are pretty much just trying to play and beat the 3 Arkenstone modes. Play modes until you beat one, play Smaug mb, play Beast multiball, play Feast Frenzy. That's cool, but no mini-goals along the way. With WOZ you're trying to get to Melt the Witch. So play Emerald City mb, play Rescue mb, play munchkin mode, play fireball frenzy, play Haunted mode. The difference is there are mini-goals to each of the WOZ "things to do". Play all munchkin modes to get Munchkin multiball and collect a diamond. Play all haunted modes to get Haunted multiball and collect a diamond. Beat ECMB to collect a diamond. Quench enough fireballs in fireball frenzy to collect a diamond. Beat Rescue mb to collect a diamond. Throw in Crystal ball modes, HOADC, the yellow brick road, throne room, oz lanes, Glinda awards, and the two outlane games and you have a full package. Hobbit is lacking "diamonds" to collect for an ultimate goal and mini goals to go for along the way IMO. It would be cool if say you completed all Gandalf modes you got a special multiball or mode. Same for each race and Bilbo/Radagast. Or play/complete 10 modes, get some award. There is no real incentive at this point to beat/play more than one mode between each Arkenstone mode. The goal is just to get to the next one.
Saying that, it's still a fantastic game and one of the deepest ever. I think there is more yet to come to bring it to WOZ level though.