Wow, I loved the battles in this game. I was gonna say that I'd love a bigger game with this Dress mechanic but I see you said the system was inspired by X-2... I've never played X-2 but this definitely made me interested in its battles, at least.
I will say that I found practically no use in thief, but the other 5 classes were fun to shuffle around. I mainly used Idol, Mage, & Gunner, but had some nice uses with Warrior & Priest. I didn't actually mind the health of any of the battles or bosses. On another note, I cant tell if it was my laptop was taking too long loading the battles, or if they actually take about 10 seconds to load in.
Also yeah everyone's said their piece about the final battle, and I basically agree. I do appreciate that the dialogue was different after each loss which made it feel like it was progressing, but yeah, either lowering the count or making the boss instantly 1-shot you each time to make it quicker would've helped.
Anyway, this was a fun, short game! I'll probably play it again just to experiment more with the classes. That part really was fun.