Decent two player co-op experience. One player acts as the information provider (the librarian) and the other player actually interacts with the puzzle (the explorer). I played as the explorer and had a ton of fun and so did my friend. I wish they could have switched up the roles for some of the puzzles. There are minor bugs but nothing too annoying. It's still great for offering a fun challenge at the low price of being totally FREE. Grab a friend and try it yourself.