install linux in a virtual machine or compile it yourself or windows subsystem for linux (if that even works i use manjaro linux btw) supertux 3d is a game made for linux not mac os or windows so adding a mac os and windows build will be a afterthought (installing linux would be better )
(Sorry for necro posting) This was made using the Godot engine, which has easy options for exporting to most platforms, so there shouldn't be any excuse to not have prebuilt versions for Windows (and maybe even Mac) imo. This is coming from a recent convert from Windows to Linux. Though you can compile yourself using your own copy of Godot.