Alright, back with more news.
Kunai Novice, Antlion Queen and antys are all a-okay now.
I've gotten to Clampula and the Mama Spitter though, and I have to say I'm not too impressed with them as they are right now. Clampula just feels like a more boring version of the King Slime fight, jumping around and not really doing much to be challenging or unique, while the Mama Spitter 1. is a bit too weak, and 2. makes little sense in its attack pattern.
I'll focus here on Mama Spitter since that's one that can be delved into more deeply beyond "flesh out this boss's abilities more pl0x".
I'm able to kill it under a minute with just a minishark and superball bullets from Calamity, which are 2 damage higher than meteor shot and have extra rebound properties, nothing enough to significantly boost my DPS from what it would be with just the minishark, and the little minions its supposed to have die so quickly to my minions I don't even get to see what they look like. Oh yeah, and it's damage is kinda pitiful.
Anyways, Mama Spitter's AI: From what I've gotten it does three things. It either hops around to wards you slowly, which is fine (needs a better animation for that if possible though) hops towards you really fast (which needs to be slowed down. the faster hops are almost impossible to avoid) and spawns new thingies (which is fine.)
I'd perhaps give the mama spitter a ranged attack of some kind? Perhaps a lobbing one? And also making the hops seem less random.
Also, the Mama Spitter has an ugly sprite. It was sorta jarring when I came up against the Mama spitter and, completely unlike everything else from NU I've encountered so far, it doesn't feel good. The animation is clunky, the sprite is ugly, it just doesn't match up to the quality I've come to expect from this mod.
Anyways, good potential here, just stuff to go back and work on.