There's a lot of things I dislike here.
One, the respawning enemies. While normally this isn't a problem, it's too much of a challenge to suddenly have annoying bad guys you thought you'd removed, and even more so when you're forced to restart an annoying battle like Nanoswarm or the last boss.
Two, no really new concepts were added. Sure, amotic power was nice, but only one was strictly needed to beat the game.
Three, the 'dog'matic structure of "dogs = good, cats = evil". (See what I did there?) Why is it ALWAYS that the cat is the bad guy??????
Three-and-a-half, it was too bloody obvious that Kitty was the final boss!!! I'm not even marking this with a spoiler alert, since it's so obvious!!!
Four, you retconned Fishy. I never beat Fishy, but he should be here!
All in all, I just can't stand what you did with this game. The graphics are far from anything new, and neither is the gameplay or story concepts. Please don't make any more of these.