Zipper is a smart game, with a satisfying gameplay loop - the mechanics are deceptively simple but surprisingly deep. Almost every time I rushed a room, I paid for it even when I thought I had a good grasp on the game. The sound design is fantastic here, with great atmospheric music and awesome sound effects. The artwork looks excellent too.

It's a little bit mazelike for my tastes, hunting for a random key can be a bit tiresome especially as you lose all progress from a single mistake.. but I can see the appeal also.