I used MisterX's post to respond to, since his included everything posted above him :p
The combat felt nice, but it got repetitive in my opinion as it never required me to really use my skills more or less tactically. Also guarding and the combos didn't seem to be of use.
Sorry you felt that way, as both can be used very effectively. Because of the generous health pickups, you could probably get away with just mindless running and attacking, but that doesn't mean you can't use any finesse. The game is easy to keep the casual player entertained, but the depth is there if you look for it.
Another thing I wondered about were the unlockables. As you don't have any choice over which skill you want to unlock next and the "currency", those targets, is plentiful, I didn't understand why you had to buy them in the first place, anyway. It seemed like they could have just been rewarded at the end of each level.
Hm, not quite. The targets were plentiful, but if you weren't playing mindfully they'd be easy to miss. In order to unlock everything in the game (i.e. the bonus cutscene and Boss Rush at the end) you'd need every single target, so even if you could get by earlier on missing a target here and there, you'd want to go back and get them later. That's replay value for yah!
Lastly, I agree that a bit more effort should have been put in the writing... but some of the dialoge was just too obvious. For example when blue says something along the lines "Why do I need a partner? I'm already pretty awesome on my own!" His huge ego doesn't need to be shown that obviously, one understands that he is very sure of himself even without the use of "awesome"
It's true I didn't do as much editing as I could/should have, and that's a great example. As they say, live and learn!
Thanks for the replies and feedback, everyone!