You have to play this game!
The various combos that are available using Kratos' Blades of Chaos, and the magic that you can learn keep the game interesting. Sometimes hack and slash games get boring and monotonous, but not God of War. The puzzles are also difficult enough to be fun and not trivial, but not so difficult to become frustrating.
If you haven't played God of War yet, I highly recommend you check it out!