So I believe I finished what has been done so far and I think it's a good start. Here are some notes/thoughts I've had while going through it:
1. The art direction is really good! I did notice that it's hard to track the PC if you're in the starter form on the second stage. Other than that, each form is unique, varied, and nice to look at. I wish the first form's color would change to like a light green (mint perhaps?) for some visual difference.
2. From playing the game, it never felt quite right to get a double jump until the end of the game. It might feel better for each form to have it and for the air form to have potentially a triple jump and/or a second air dash to give it some unique qualities.
3. The three-hit combo feels rather sluggish and slow, and having barely any hit-stun on the three-hit combo does not feel good. Often times, I get hit when I'm attacking mobile enemies when I try to recover energy. Either the enemies keep on coming or they get knocked away before I can finish the combo.
4. Having a small amount of energy regeneration when it comes to level traversal can go a long way. I found myself nearly soft-locked when I ran around looking for enemies to get energy to open up doors with fireballs or the E ability in the first form.
5. I'm not going to go too far into the story since there isn't much to work with, but it didn't keep my attention. Lore is nice to have, but my drive to learn more about the world feels hampered. Plus I liked the little rabbit guy and would have been nice to see them staying around longer.
6. The bosses in the demo are fun, but there are bits of them I want to address: the character hitbox is too big to dodge the bricks falling down in the first fight. Often times, I would try to fit through the smaller cracks thinking I could fit if I managed to aim it right, but I'd always get hit and it didn't feel great. The second fight with the robot vulture (I think it's a vulture anyway) is better, but having the boss dive from the sides of the stage felt strange to have to dodge. Plus, the tornado attack needs to have either a form of windup or a visual tell so the player knows it's coming. It's not the end of the world, but it would feel better if the player could get a quick visual cue to react to a mechanic that's mandatory to damage the boss.
Overall, good start and I'd love to see if/where this goes in the future!