Thanks a lot for the detailed and kind feedback, it's really appreciated!
I think you're right: with only one attempt, the tea mini-game might be a bit unfair. We will definitely consider a "retry" option, or maybe let the difficulty increase gradually. At the moment, you obtain a good review if you manage to get at least 10 points; we though it was a good threshold, but in fact we had no playtesters to confirm that! I'm sorry that you had to be the one, but I hope at least that it didn't spoil the game experience!
Also, the "practice area" (a sort of endless tea-blending sandbox) is a great idea! Maybe in the future we'll add it, who knows :)
Thanks again for your precious comment, we're glad you liked the game! ^^