This game is very fun to play, although it is noticeably unfinished in a few ways (but that's expected as it's an early demo). There are some bugs, mostly with scrolling issues, and there are a few quality-of-life improvements that the game would benefit greatly from, such as making background tiles easier to place and use. The ability blocks, the blocks you can only break with certain abilities, don't work very well. As far as I'm aware, only the fire and rock ability blocks work as expected. When the other blocks are attacked with their abilities, they do not break. I couldn't help but notice some sword and boss files in the game, and I won't lie, I can't wait until they are put to use! Some suggestions: A water ability (there are several water enemies in the game, so a water ability would probably be good to put there), water tiles, a sword ability (there are some graphics files hidden in the game), a UFO ability (there are a few sfx for it), ability essences (or ability bubbles in the files), more bosses like Wispy Woods, King Dedede, Meta Knight or Kracko, the ability to see a door's ID at all times, slopes for every terrain, the ability to change the music multiple times in one level (maybe by doors or invisible triggers), partners like Rick, Kine, Coo, Pitch, etc., and (if you can, of course, this is very ambitious) maybe some extra game styles like Kirby Superstar or Squeak Squad. I love this game and I can't wait until the next update!
Here's link to the Wine website if you want to look into it: https://www.winehq.org