While it's not really my thing, the game seems to play the way you wanted it to, and I can't knock it for that. I haven't played Ikachan, so I lack context for some of it, and everyone else seems to have enjoyed it. But, I do have a few criticisms.
First off, I think it's a bit cheesy that you have an arbitrarily high amount of healing items in the final boss room. I understand that it's a game jam game, and it's hard to get the balance right in a limited time frame, but I think it would have been better if it was possible to "waste" them by picking them up at full health, so you had to be at least a little bit more careful.
Second, and more importantly, I think that the game lacks a sense of scale. That's what the game jam is themed around, and while you say that everyone was shrunk down, that isn't really communicated by any of the graphic or stage design. Could really have used some random objects for scale, or maybe a giant enemy bug...
Viewing post in Honey! Cirno shrunk the Fairies! jam comments
I actually did try to communicate scale through the tilesets, its why some things look bigger, but i might've not have done a good job at it. I also did try to make the fairy enemies big at one point but they took up a lot of space and just looked weird. either way, yeah i do think i could've done better at it, it was just kinda hard when i tried to communicate that while also having time for the bigger stuff. (like the final boss)
also, i actually like the idea of wasting healing items, i actually wish i did that now lol