Pretty cool interpretation of the theme, nice entry!! I really like the concept of the walls slowly caving in, it fits the theme well and also adds a lot of tension to the gameplay. Having to time your shot with the revolving circle was fun too. I think adding some screen shake when you get hit by a bullet or some text that says something like "Player 1 Won! Press R to try again" would add some nice polish too.
The minimalistic art style is great but I think everything could use either thicker lines or filled in with color, as its tough to see what is happening with the thin line work. The music is nice and crunchy and fits the overall aesthetic very well.
Overall, I think this has a lot of potential as a 2 player game with a friend to have some arcade-style fun, good job!