For a first game jam project, great job.
The gameplay was very simple. Tank controls are tried and tested. Game could be difficult at times, but it ramped well. That said, it was very simple and got tiring after a short time (about 5-10 minutes) (2)
Graphics were simple but communicated effectively. Thick outlines for walls were a good choice, and you could tell what enemies were. Colors were also nice. The art is however too simple to be able to rate highly. Definitely room for improvement, but you understand the design aspects of art! (2)
The game is very simple, and very tradition. Tank control top down level navigator where you avoid spikes and saws. I also fail to understand the connection to the theme. (1)