Sadly nothing that special that will make me come back to play this game.
I liked the music, despite the fact their looping is pretty noticeable and deserve to be longer. You have the potential for a story with the introduction, but it doesn't go anywhere beyond that. The fact there were instructions right at the start of the game was appreciated for first time players.
Being limited to left/right movement in combination with a single enemy type, and nothing to make the game feel like it's changing or that your progressing through it the game gets old pretty fast. The main two things that made me come back to it was the music and the desire to know if there was going to be any progression the longer I survived.