I found the F and H super confusing, I also thought that was the temperature and not the amount until reading the comments.
A reset button would have been really nice, but I see other people have mentioned that. It would also be nice to see how much sugar/pearls/ice are left so I can tell right away if I have enough supplies to even make a drink. The time limit for each order is also super tight, if you make another version of this game it might be good to have the time limit at least start a bit more forgiving. The one other big criticism I have is that the sliders really don't feel like the best method for adjusting price, it would be a lot easier to just be able to type a number in instead of trying to find the right number.
Overall a great start for a game, would love to see it expanded and could see it becoming a super addicting little game!