after some thinking and experimenting, looks like i found the way to make good, balanced research system for my game.
How will it work
- i will call elements from periodic table "metals" and elements from research game "elements", otherwise whole post will be annoying and hard to understand
Firstly, to do some reaserach you require special metal for each try (it goes on top of couldron)
Then you can add another metal as catalyst (it goes on left side, before step counter), it wil unlock random step even if you don't match anything
Then goes grow-like matching game. You can't use the same element more than 1 time now. Also if you unlock step, you have to follow it, or next researches will not work
After selecting all elements click "research"
When you finish the research it will unlock new recipe for cauldron or some other stuff
short vid about new system
*thanks to @benjamin and @wan for ideas that helped me to make new system. *