I'd personally like to see the code being more organized into objects instead of having createobjects.lua, drawobjects.lua and the logic being in main.lua. I get the argument that self might be a bit complicated for total beginners but having stuff organized into their own files doesn't mean you have to use self or code everything with OOP in mind.
Regarding visuals: I made something simple that could be used as inspiration for the game.
The UI elements are borrowed from an older unreleased project of mine.
The terrain is made out of tiles and 3 separate tile layers.
Implementing tile based terrain might be a bit too much of a stretch for this type of game aka too hard to implement with collisions and random terrain generation - but I thought it looked cool
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Also Imo the gameplay could potentially be better with smaller sprites and terrain and slower gameplay overall - a bit more like the original game, but not too slow.
For more diverse gameplay I could imagine the game having some simple random encounters or events on the way like the engine struggling to fire (rarely), random astronauts appearing that need to be taken to the next base, a tornado that has to be avoided or asteroids.
I use a limited palette 
