This does not run on mac's using Sierra. A great pity as I wanted to play the game.

This is a great game. I love the Rube Goldberg/Heath Robinson style of very complex and clever techniques to accomplish simple tasks. Some of the levels are extremely challenging and others very simple; a couple of times I thought there must be a bug because a level seemed so hard to finish but every level can be done - sometimes you need to be very precise with placement. The game rewards creativity - you can accomplish the tasks any way you like but the set-up sometimes requires you to do counter-intuitive things with gears, magnets, explosives, lights, boilers, steam engines. It's like a virtual marble run for adults. Totally worth the money and you can play it for many, many hours.

Purchased this game down loaded it and can not open it once it was installed. I got an IMac and this is the first one that has done this for me.