I found this game quite fun. The pace was pretty good and the controls were responsive, which is important for a bullet hell game. The sound and music were good, and the cutscene at the beginning was amazing.
I found moving around in the empty space a little bit disorientating sometimes, since there is nothing really changing on the screen. This could easily be fixed however using a bit of background parallax. I also think you should make the virus spawn outside the boundaries and move into it (like you did with the boss) because sometimes a virus would spawn right on top of my ship and damage me.
Overall, a great and polished game. Good luck in the game jam!