But, as others have mentioned, you run out of vowels or consonants a lot, which forces you to start a new game when you have many lives left. Of course, this is not the fault of the player...
How about making a shake to scramble the tiles when you get stuck or simply restack the level. The game should be smart enough to know when the board is loaded with all consonants or vowels.
I've also found legit words that were not accepted, like Rome, as well as some others, including names.
Fix these issues and I'll give the game five stars!