Hey, I played your game. I immediately liked the atmosphere. However, after a few levels it felt monotonous. Aliens did spice things up a little, but the game doesn't ramp up in difficulty (other than areas getting bigger and emptier). Maybe having some more variety in obstacles (fast flying asteroids, shooting alien ships etc) could help. Once game feels more difficult, maybe add some kind of hints of where to go. For example some kind of radar functionality which tells you the distance to Earth (usable with cooldown to prevent spamming) or indicator which blinks faster as you get closer. Having to wander in the darkness for minutes doesn't really feel like its hard, but just taking up time.

Other gameplay additions could include boost button, which would make you faster at the cost of controllability (think about dash from games like Celeste).

Fuel could be limited, adding to anxiety feel if the game aims for that.

Graphics wise, you could try add some parallaxing effect to background to add more third-dimensional feel.