Really awesome idea! The mechanic of combining elements in your gun was really cool, and I liked how different enemies had different elements they were weak to. I also liked how the water gun was used to boost the player up, that was a cool movement mechanic. Some element combinations were missing and I found it odd how pressing the water element instantly filled it up, but I understand if that's just due to jam limitations, as this game seems pretty complex to code. The game really needs to let the player learn the game mechanics before it throws them in front of an enemy, since the mechanics are pretty complex. I lost 3/4 of my health to that first enemy just because I didn't know how to shoot or mix elements and the game didn't give me time to learn. Also I got softlocked in a pit:
But overall it is a really cool idea, if you add more unique interaction to mixing elements this definitely has potential to being more than a game jam game!