Since you mentioned a .rar file specifically, here is a "technical review" of that experience:

Before you extract that, run it through a scanner like VirusTotal . If the file size is tiny (like under 2GB), it’s definitely not the full game. Summary

Getting a file named Goat-Simulator-3.rar is a bit of a "red flag" situation, so I’ve drafted this review with two perspectives: one for the (the actual chaotic experience) and one for the file format (the technical side of things). The Game: Chaos Incarnate

This is where the game shines. Adding three friends to the mix turns a chaotic sandbox into a literal disaster zone. It’s some of the most fun you can have while accomplishing absolutely nothing.