I haven’t finished Opus Magnum. When I play most games I finish them quickly if I like them; with Opus Magnum I love it too much to move on. Opus Magnum is a puzzle game. You build machines that combine, transport and transmute elements to solve problems. In most puzzle games, I finish a puzzle and move on to the next, so I can see the challenge and start thinking. Opus Magnum’s changed that. Every machine that does its job can be made more efficient. It can work more quickly using less space and fewer parts. It took about ten minutes to solve the game’s first simple puzzle, Stabilized Water, but since I completed it I’ve returned three times with ideas about how it can be modified and made more elegant. Opus Magnum’s made me play differently, and that’s remarkable.