After reading some of the comments here, I finally gave this game a chance. I rented it for the weekend and finished and I must say I enjoyed it greatly.
When I tried the demo months ago, I totally hated it, maybe because the worst part of the game for me was... the tutorial. Boring and some movements aren't properly explained. Overall, I think the tutorial doesn't give the impression the game deserves.
So, after playing it all (easy to finish, but that's not necessarily something wrong) I think they deserve a lot of credit for creating something new in first person games. The gameplay, once you master controls, is great, even combat can be satisfying sometimes.
And of course, the art direction. To me, LBP and this game have the best art direction I've ever seen in a game. Very very professional, perfect. Even the cutscenes were nice and stylish, even if they are not fully 3D.
They could have make it larger, added more varied gameplay here and there and, IMO, they could make a 2nd one with more open maps and having some adventure elements thrown into it. But it's a very good first attempt.
I really thank you all guys for making me play it. It's been a nice weekend playing it. Creativity and originality are always winners for me, and this game has some.