This was a fairly fun game, I really liked the concept of switching the ground between solid in liquid.

Tips(please don't feel pressured to do these as they are my personal opinion):

1) Bugs
 - You can fall through the platforms if you  hid them from the right angle
 - Im gonna guess that you are using transform.translate for your character movement because that is what I associate that bug with, consider using rb.velocity instead.

2) Level Design
 - The level designs are a bit funky and don't really bring out the most of the switching ground state concept.
 - On the last level I basically was yoloing until I dropped in the right place which really docked my enjoyment. In other words, It was hard to see where I was supposed to go in some levels which is a common issue in platformers. Consider adding arrows.
- Consider making the levels longer and harder while making some jumps only possible with the state switch(like lvl 1). Otherwise it feels like just a normal platformer or just state switching(like lvl 4 i think).

3) Movement and Key Choices
 - Maybe switch out "alt" for a more common key like "enter" or "shift".
 - There were multiple times where I was trying to enter the door but was hitting the wrong key.
 - The Jump felt just a bit low.

4) Themes
 - Just a common theme that may work well but you could consider changing metal to ice as water kinda freezes into it and it makes a bit more sense.

Other than that, I really enjoyed you're game! Hope my tips Helped! 

Give my game a try if you would like: https://kevz3742.itch.io/elemental-arena

I really like your game, the controls were a bit hard for me since I have an AZERTY keyboard (but it's fine, it added a bit more challenge, which was nice)

That was nice, I liked it! I would have made some blocks less distant from each other. All in all tho, considering this was done in 3 days it's a good result! Nicely done <3

(and yeah the controls were a little odd but with some trial and error I got them xd)

Cute game, but... some notes for you to improve

- The choose of those keys are very weird, maybe use some common ones to help the player. (Like UP to enter a door or E to interact)
- Leaps of faith aren't that good for game design, the player will be confused if it's doing the right thing or not

And not much else ♥ Very cute game, really good job