Okay, I realize that this is gravedigging, but I feel I just have to say this...
I have not tried your nude mod. I'm not really into nudity, but the fact that you're such a devoted fan to do this really shows just how much Aquaria matters to you. Good job, though since I didn't download it, I can't really say that.
As for your costume mod...
It's AWESOME. This is exactly the type of mod I was looking for, just one to mess around in, and have some fun outside of the main game. Your mod reminds me of that Beauty of Aquaria mod, except you one-up Beauty by giving us the forms.
I do have one complaint, though. If you try to exit the Upper level (the one with the jars and the portrait) through the right side without opening the Energy door, Naija will get stuck in the barrier and not be able to get out. That really stunk for me to discover that.
Other than that, though, superfluous mod. And, I LOVE the Secret costume (definitely made my day, seeing Naija in the Zero Suit...)
Again, sorry for the gravedigging, but again, I felt this needed to be said. You really are a talented modder, Mr. Alphasoldier.