Super Mario 3D World is great, maybe it wasn't the grand 3D Mario adventure the world was waiting for and a linear, more akin to the 2D Mario adventures at that, but it's still the best WiiU game if you asked me. 15 hours is pretty optimistic, maybe if you breeze through it and not bother looking for all the secrets and playing all the levels. I've put about twice that into the game, and I'm not at a 100% yet. Pretty different from the kind of games you describe though obviously, but appearances can be decieving as it's at least a fairly challenging (not too hard though) game and finding all the secrets is satisfying I'd say.
Hyrule Warriors is fun, but it's probably best to be either a Zelda fan, or a Warriors die-hard. 10 hours is true, for the story mode. The game however has a couple other modes which could potentially give you a near endless amount of replayability, among which the Adventure mode, which includes hundreds of levels.







