Then in that case you have a modified version of Linux. This means that in order to play this game you either need to:
(a) Install a Virtual Machine and have it run Windows/Mac.
(b) Use a bunch of third-party programs that allow you to run Windows/Mac programs. Just Google, "how to install windows games on chromebook" and you'll find dozens of options.
(c) Beg the developer to create a version for Chrome OS.