I kept thinking I could use a B as an E. You have your own engine? That's cool. I felt like the game played a little slow, and almost boring (maybe I'm just playing it wrong). And with the font it was really difficult to see what words I have. I got the powerup that restocks 1 every time you validate 1 tile, so I just built words up one letter at a time. Maybe it would be good to reward larger words, but then it would the same as 90% of scrabble-likes. It definitely helps to have memorized many 2 letter words.
I'm really impressed with how much content is in the game. Good game!