Hi there! Cool concept.
I see that you are trying to replicate fluid substance. I did the same in my previous game. Some suggestion from me, you could try making the collider smaller than the sprite so objects appear more seamless. ;)
Also I'm not sure if it's a bug or just physics, on level 4 some fluid stays on top of platform at the end, and prevent me from continuing the game.
Keep up the great work!