I just got the game and have played about 3 hours of it. In the first couple of hours I completed the first two rank missions, played six of the different minigames, and did one revenge mission. I've found that I love the overall style of the game more than the actual gameplay. The combat is already starting to feel repetitive to me and I'm starting to think that it won't be enough to sustain my interest for much longer.
 
Is what I've played so far a good indication of pretty much how the rest of the game will be? Please tell me it gets better...

From what I remember it gets harder, but doesn't necessarily change much. Just go exercise your cat and revel in the greatness of doing pointless activities.

If you don't like the combat, you might as well just stop now.

The 4 beam katanas change up the pace a little, but you wont be learning any new moves.