Thanks a lot for trying out the game. Yes, I also want some indicators on screen for Asteroids that are off-screen. At the moment only one "field" of asteroids is spawned. I am currently working on a system that will automatically spawn new fields when you move around. There is really no game there yet. I need to get the spawning done. Then I will look into other elements like collisions and other miners that might attack you.
Thanks a lot for your comment.