I played for an hour and got bored. I wasn't going to comment because I feel like I need to give it more time to give it a chance, but hearing that you beat it in under four hours I feel like I'm 25% through at least and have a pretty good idea of what the game is like.
It would have been fun if it was faster paced, on top of it's repetitiveness, Jack feels slow and tankish. A beat em up needs to be more responsive with an agile character. (Not to say it can't be done with a wiimote, NMH for example, I wasn't a huge fan of NMH either, but more so because of the lack of polish and job system. Combat and bosses were a lot of fun in that. Albeit it did get repetitive at times too.)