This is a great game, but the major reason I like it so much more than all those other puzzle games out there is that you keep going. In a lot of games, you reach to a certain point where everything before that was fairly easy and solvable, but this one you can't get past. This is where they get money off of solution "keys" and other stuff. This game, however, you just have to think some to solve it. There's no level that's so complicated that those people who make the walk through must have made the game, too. Overall, worth it.