Rules of the Game
Write a word and send it to your opponent. If your words do not match any vowel, for each different vowel you earn 2 points. If at least one matches, you both lose 1 point.
In the middle level, the penalty for matching is proportional to the number of vowels.
At the high level each vowel counts separately, that is, for 2 equal vowels you can earn 4 points. But the penalty for matching is triple the number of vowels used.