After five hours of gameplay, here are some impressions for Letter Quest: Grimm's Journey:
The graphics: Simple. The backgrounds are nice and not too distracting, the characters have some charm, even though a lot of the villains are almost entirely monocoloured, and you're allowed a little variation in the letter tiles as the game progresses, most of which are nice (but the "words with friends" style is not easy on the eyes at all.) It does a lot with a little.
The gameplay: It's good. You're given a board of fifteen letters, and form words with them to attack monsters. It plays closer to Bookworm Adventures where you can use tiles anywhere from the board, than it does Words for Evil which requires adjacent letters. Tiles can gain bonus-granting crystals which appear randomly, but sadly do not seem to appear if you form a great word - and penalties of various kinds supplied by the monsters. Each level must be completed four times: once standard, once timed, once with an extra challenge, and once where the monsters are "elite" versions. At first, the "elite" levels are quite tough indeed, but after you get a few passive bonuses under your belt, it's not so bad. And yes, there are lots of upgrades to be had. I'm pretty good with words - one of the first achievements I unlocked was getting the requisite number of eight-letter words - so I'm finding that the game ranges from easy to mildly challenging.
The controls: You can use mouse to click the letters on the board, or just type on the keyboard. Typing is way faster, but you'll find you'll need the mouse at times. Some monsters have attributes such as "Takes double damage if you use two or more letters in the top row," and if you type out the word, it might use that "A" in the bottom row instead of the one in the top row. Later on, monsters might ONLY take damage if you use letters in certain positions, so you'll actually have to pay attention to see that the letters you want are in the right place. The letter-picking algorithm doesn't make it easy on you.
The audio: The music is nice, but at times I found it swelled too much and I had to turn the volume down to avoid getting distracted. When you're playing a game that requires you to think, well...you need to hear yourself think. Sound effects are a bit sparse. I would have liked hearing more audio out of the monsters to give them some depth and personality.
The verdict: It's fun. It's not perfect, it's not terribly hard, but it's fun. I'm enjoying myself, but I do hope the challenge gets ramped up a bit.