The only aim in Rust is to survive.
To do this you will need to overcome struggles such as hunger, thirst and cold. Build a fire. Build a shelter. Kill animals for meat. Protect yourself from other players, and kill them for meat. Create alliances with other players and form a town.
Whatever it takes to survive.
1. Download, install and run installer STEAM.
2. After the game run, create your STEAM account according to instructions on screen, after that go into tab Games, options for product activation on Steam, copy the game bought game key from your KeenShop account
3. After this procedure the game and it's parts is present at Games tab.