The level contains a bunch of strong Red enemies. Enemies progress from a cluster of buffed Sir Seals, a Shy Boy, then a H. Nah. After the second H. Nah, the enemies will stop spawning and you will have no other problems.
Kiss and Koi is powerful and very fast moving, but has a moderately slow attack rate. Paris stacks or anything with a range of over 400 will take it down in short order. Also Kiss and Koi are a floating enemy so bring along an anti-floating cat.