This series has always been on my favorites for the story, but this last game really made me start thinking that Crystal Dynamics needs to rethink the puzzles in the game. Well, starting from the top.
The graphics are top-notch for this style of game. The backgrounds work well as do the character designs. I especially like the main character models as they look awesome. Not so much for other minor characters.
The sound needs work, in my opinion, because there is so much space where there actually isn't any. I noticed that the game tries to keep moving by integrating loads as part of the game, but the lack or presence of music made it awkward. The sound effects are sometimes on cue, and sometimes they miss. The music during the levels is spot-on for this setting and with surround sound, it sounds even better. All games need surround of some sort.
Gameplay: it gets very repetive. For Raziel, find abilities for the reaver, Kain, find out information. Puzzles, puzzles, and more puzzle, but not a lot of backtracking which was really nice.
Now the problems. There are a lot of collision problems in the game. You can't hit enemies when they first appears because they have entrance animation. I got locked out of the board by a border in a room which sound have kept me in, on several occasions. Some puzzles are very vague, and some are in your face. Really the main problem is I felt that I was doing the same stuff I did in the other games all over again. And it kept going in my head, didn't I already get all the reavers for Raziel in Soul Reaver 2? Why doesn't he have them anymore? ARgh, this puzzle make no sense!
All in all, I play for the story because it is the best quality of the game, you should too, just expect to be a little aggrevated with some of the problems.