$ make install
Or
$ go get github.com/Peaupote/ludum-dare-41
You can also clone the repo but worry about the $GOPATH
then
$ make run
Or
$ go run menu.go physics.go simulation.go universe.go player.go main.go
Or
$ go -o SpaceCruise build menu.go physics.go simulation.go universe.go player.go main.go
$ ./SpaceCruise