Wow, super cool idea. I'm impressed, although I was hoping to kill that big boss ;) Thanks!
A downloadable game for Windows
"ANTIVIRUS" - Made in 48 hours for Ludem Dare 38 - Theme "A Small World".
A virus is attacking your computer! Journey inside and shoot the heck out of it.
[Edit - Bug Fixed version uploaded 29/04]
Download it, unzip it and open it. You might get a warning from Windows because there's not a known publisher for it.