We apologise for the delayed feedback:
I really like this interpretation of the theme! As an antivirus software fighting viruses that are trying to infect your machine, you are absolutely the weapon against those viruses. I love the idea of the computer being represented as the Wild West and that you duel it out with viruses in an old-school style shooter. This reminds me a lot of the movies Tron and Tron: Legacy for their interpretation of the computer being highways and buildings. The music has a nice ambiance, the sound effects from the gun shots and when a virus gets through are solid as well. I think my main suggestions would be to keep improving the art (already great, and I can see how awesome it could be in the future), add more custom music, and refine the UI. The shooting mechanics are simple, so adding some sort of waver to the targeting would make it feel a little more difficult.
Your GDD is pretty well laid out and descriptive, though your development progress section is a bit chaotic. I understand that can be difficult to figure out how to implement and keep track of, so no judgement there! I like the sketch layouts of the main two screens, but more detail on the UI wireframes or other mockups would be good to see. The mechanics are simple enough to not need a lot of detail, and the download progress bar is easy to understand. I also would have liked to see the roles of each of your developers in the GDD: this can help also keep everyone on track and keep duties separate as needed.
Overall, really enjoyed your game! Awesome job on using new software and exploring new art styles. Thanks for this submission to the game jam!