The instructions on this game contained on the screen are written in a specially designed character set. It seems odd that programmers can go to the trouble of doing this and then say a 'missile flys' at you and that it is 'indestructable'.
No one is perfect, and typographical mistakes can occur and fail to be spotted, but there should be no excuse for such poor spelling in a game intro. As for the intro, it describes Orpheus as being a task to deliver a secret document to headquarters by way of an enemy occupied tunnel. The enemy will send Tai fighters at you, which by some odd freak of nature are alternately destructible and indestructable.
There are land-based objects like Quarsar silos (remember those?), fuel dumps and etcs. (whatever they are).
The screen view is looking down the length of the tunnel which is represented by two converging lines and a ragged tunnelish line which zooms out in four frames to convey movement. The various land-based objects (etcs. must be the purple pyramids) grow bigger as you fly over them. After a while the fighters come out and then a real protagonist with heat seeking missiles.