Nice, I noticed a little hint of Breath of Fire, nice style.
Yeah, when I read that you were planning on making a hack with this I was kinda worried, 16-color pallets can really be a pain, but since you're going custom you shouldn't have to worry about that too much now. Good luck with this.
Oh, and I can't see the spider one, I see a rock thingy and a worm but both of the ones that I can see look fine. Remind me of Aron and Caterpie.