Install Windows 10 using BootCamp, on your OS X install VMWare Fusion (free) and create a virtual machine using the existing BootCamp partition. Open virtual machine's settings and set more RAM for it (maybe more cores if the mac has more to spare
). Also don't forget to uncheck "Use full resolution for Retina display" under VM settings > Display or the game window will be like 5cm x 5cm (translated as 2" x 2")