I really love this game! I like that it's more puzzle-y than fast-paced. The many tools, the restocking swaps, the convenient undo button, and the layout concerns all combine to encourage building really fun, long words. 

There's a few things that take it down from five stars, for me, and which I'd love to see addressed in later versions:

• The dictionary is sometimes lacking. This is a big quality hit, especially when I'm having fun with building interesting words. It's disappointing to find a word like "quine" and not have it register.
• The first few levels are really same-y. This seems like it would be super easy to address. I was expecting to have more variety in board layout, given the "must use all letters" constraint; just varying from the five-by-five-square layout would add a lot of interest.
• You can't undo a swap (or other tool use). This is particularly frustrating when it combines with the dictionary not recognizing the word you just put together.
• Since the levels are randomly generated, sometimes you get a really rough starting layout, and there's no reward for making it through that. I think it would be nice to have a personal high score for each level, where you'd get more points for making long words with tricky letters.

Of these, the dictionary and the undo button are the ones I'd consider actively problems; the others would just be nice bonuses. Altogether, though, it's perfectly reasonable for an indie game, and I'm getting a lot of fun out of it.