Its a very cool game. I like how you added an Online Highscore and 2 languages. Are you German or did you just use a translator? Im German and I would advice that you use something like "Schreiben" instead of "Tippen", because "Tippen" sounds like you have to click with the mouse or with your finger (on a touchscreen). I knew that I had to type the letter because I read the English text before I changed to German and the water drops display a letter but it may confuse some people.
I also have a couple ideas for the type mechanic. I don't know if you've already implemented that but don't let drops with the same letter drop twice in a row. It can happen that a player tries to hit a water letter last second before it disappears and the same letter appears as hail. Also you can block the keys around a letter so that if B is water V isn't hail, so if you've misclicked it isn't a problem