I bought the add free version, played it fully, finished and started a "next level", i dumbly selected alask to start (not knowing what the mechanics of the next level are), and now i don't have enough keys to unlock anything else in the map. so i'm basically stuck with a screensaver, without access to anything else as the game doesn't even allow me to select settings. I enjoyed the game, it would have easily been a 5 stars, but being locked out of a purchased game feels like i should get my money back.