An interesting little game. I love the AMAZING cover art and the moody techno-thriller vibes! I also thought the character customisation was a nice touch! I can see this coming in handy if a co-op or party mode was implemented. I can actually see Space Hitter as a battle royale / last-man-standing type of game if it were to be expanded upon. Generally, the game was enjoyable - but I felt like the execution left me wanting.
I think the red screen with the "Start" and "Quit" options was unnecessary as I'd already clicked "Play" on the character creation screen / "Restart" after dying in order to get there - so I obviously wanted to start the game 😅.
Also, IMO, the "Game Over" info should just be in a pop-up in instead of on a completely new screen - and then the artwork of the character could be used as the background on the main menu. It's a fantastic piece of art - it should be shown off! Also, as it is used as the cover on Itch and as the icon for the exe file, this would make the presentation feel a bit more cohesive.
The music is great for the first menu screen and perfectly builds up some tension, but I felt that something more fast-paced would have suited the level more. Speaking of, I thought the character movement was a little slow. The imminent removal of floor tiles from underneath the character and the enemies constantly closing in made me feel a bit frantic - but the movement speed of the character didn't match this feeling.
Overall, I think Space Hitter is off to a good start - I just wanted to leave some feedback to help you take it even further!