The pixel art style is great! It seemed a bit weird to me that i was traveling into one direction all the time but the enemies came from different directions. I liked the sounds and the atmospheric music, but I feel like maybe having a bit more upbeat music would fit better for this type of game.
The multi-directions were implemented very close to the end but the enemies coming from other directions are slower (depending on the difficulty).
I didn't spend much time on the sound effects/music and the space/world ones were short so I stretched them.