Woah! What an awesome demo, it would have been nice if it said it was a demo but it was still amazing. I feel already immersed.
Tips for future builds, save option, and !stuck option. The reason I have included stuck option is because the rover got stuck on one of the object and I had to start over. Maybe if the player could type or press a button to indicate they are stuck the game could teleport the player close by.
If you need a alpha/ beta tester I'll be happy to help.