Great combination of intuitive controls with a gameloop that encourages experimentation, meaning it's okay to not explain things upfront.
The visual style is also great, love the alchemy theme, but I wish there was some way to pin the scroll so I don't have to hover over it every time, or if the combinations were more obvious. It all made sense until I saw yellow+blue=purple, and then the second and third tier doesn't seem to have any obvious logic I could discern.
Very good game though, out of the few I played it might be my favorite so far.