Somehow it took me a lot of time to see the 'Notes' button, but after that the idea was easy to grasp.
I think the only problem is that, if I understand correctly, the levels are randomly generated, so there're some that have multiple solutions. Example:
Notes: 1+3 explosion, 1+4 explosion, 1+3 hexagons.
After some tests, I got these three cases, assigned each number and the unused flask I assign the 2 value, but it was wrong. Then I did more tests and realized that the 2 and 3 flasks behaved exactly the same.
Beside that, it's a very interesting game, congrats!