Here are my last recordings:
https://youtu.be/_a2L_hn7NvA
https://youtu.be/l8ryUik3i2Q
You'll notice that I had to split the recordings because I defeated char-wuf and died at the same time, which prompted an error (it's in the end of the first video, but I also screenshoted it.
My last thoughts are: at first I thought the difficulty curve was a little broken, but as you said, this is how this games work, and I already had noticed in my second playthrought that the difficulty scale was going pretty well actually.
The two stages are very different not just in aesthetics but also in gameplay and feel, so it doesn't feel like I'm playing the same levels but with a different skin when I switch stages.
The bosses were pretty fun and balanced, as I've said before, they don't feel like the same fight with different skins. Both have their difficulties very different, in Hana-sol it was hard to move without getting hit but anything, and in Char-Wuf it was hard predicting her movement (I tried using the balls to stay away from her, but it didn't work too well). Overall, both fights were pลetty fun and full of personality :]
This is just a suggestion, but it would be really cool if mid stages I could learn a little about the boss I'm going to fight so when I meet them it would be a greater revelation.
Pixelart and music were pretty good, really made me feel like I'm playing a classic arcade game. The visual identity of each stage is great and it's really fun noticing the little details, like the "holograms" in Char-Wuf's stage. The boss theme is really well fitting, the fast paced piano sets the right mood for a boss fight and also makes it feels more like a fun friendly fight than a dramatic fight (not a critic or anything, just pointing out). Both pixelart, animations and music seems like they were made by a professional :]
I also likes a lot the revelation the Char-Wuf's stage is like a really big playground for her :D
Overall, I had a great time playing the demo and would like a lot to play the full game when it releases (and when I have the money to pay for it)! Thanks for making the game and congrats for what you achieved :] the best of luck for the rest of development! 