The only on-rails shooter that I liked in my whole life.
The soundtrack of the game isn't that thing from other world, but I can sure tell you that it rocks.
But, do you wanna know the thing that made me not give this game a 10? The length of it. It's way too short! You can beat it in about 5~6 hours! Well, good that we have the online leaderboards, so it can let you busy some more time on the game. Oh, another good is that the replay is excellent.
The co-op mode is a little strange, but OK. The P1 plays normally and the P2 takes the other character (Kachi if you selected Isa and vice versa), but all that P2 can do is: aim and shoot. Yup, he's character doesn't appear on the screen (it only appears he's aim), he can't use close combat and charge shots.
But still, I think it Sin & Punishment: Star Successor a great game, even if I didn't understand the whole history, which is a topic that I will not touch for obvious reasons.