Neat :) Had similar problems as other commenters at first, but got used to it quickly.
I found a bug where the game decided I lost before all the yellow liquid was done pouring and when it was done, the middle circle was fully yellow. It is kinda weird though, as usually it waits quite a while, even after the yellow stuff is done pouring. I think this usually happens when the nozzle is mostly blocked?
When you win, game says 'Go for the next' but then sends you back to main menu and sometimes they are really easy, even after passing a much harder one...
Anyway, definitely neat idea!