At first the game's very confusing. There's no indication to what you are supposed to do, except a screen that pretty much says "Destroy the viruses. Good luck". I had to figure out how to play it on my own.
So, you move around using WSAD, and you shoot using your mouse. Pretty simple, eh?
You have to destroy the viruses. How. By shooting a steam of fast projectiles. I don't really like the fact you have to tap all the time to shoot, your fingers get sore. The viruses shoot a lot of slow moving projectiles that can be destroyed. Also, there's a big virus that doesn't shoot, but has a lot of health and when it touches you it pretty much kills you instantly. Over the time the difficulty rises. Too bad there's no score, timer or anything to indicate how are you doing.
Graphics are kinda ugly, but i like the old computer screen filter on some menus, like the "About" one. Also other menus are weird... The terminal one, i don't know what to do here and you can't quit it. The Health indication is nice, Screen gets more red according to health. It regenerates, but if you can't dodge you are going "Shutdown", and for some reason i can't go to menu or restart after losing. Also add some sound effects, this game would be a lot better with them.
Overall, it's a nice danmaku game concept, but not too well executed. Keep working on it, and i bet this will be a really good game
Just iron things out and polish them as much as you can. You have potential, but you've got to train it. Good luck