After reading multiple threads on how to get CO2 to work on Macbook, and by experimenting a bit on my own, I found one way that works. Download an application called Crossover, this is basically Wine, and will allow you to run windows CO2 on your macbook. After downloading Crossover, install Steam by searching for it in the Crossover search field. When you have Windows Steam on your Mac (through crossover), simply find and download CO2 from Steam, and it should work. For me, CO2 only worked if i chose "Use current resolution" when deciding screen resolution, as anything else would bug out game. It seems like choosing to view "AP" range and "All" range makes the game halt to a stutter, and might even crash the game, so you might have to stick to it being on "None" It is also possible to use Bootcamp to have Windows on your mac, but this makes the UI and unit icons very small, and basically unreadable.