I have mixed feelings about the "free to play" business model. It eases in players to try a game that they otherwise would pass. However, it opens doors to microtransaction schemes, especially when bought content gives the player an edge. It's been invading fighting games as of late too, although at the moment they just add options than giving a competitive advantage.
For old time's sake, I played Samorost
, a short (can be finished in less than an hour) browser-based adventure game a friend introduced to me in college. It has a quirky, but appealing art direction, although the puzzles are semi-logical. I haven't tried any of the commercial games created by Amanita Design though.