The actual size of my game was 12.99 kb, or 13309 bytes to be precise (yes, just 3 bytes less than the limit :P) and it took me 77 hours and 23 min to complete.
Pandemia is a zombie survival shooter game with Minecraft inspired graphics where you have to come through hordes of zombies in order to deliver a vaccine to a safe zone and stop the infection, saving the human race. But wait, you are already infected, so you will start losing your humanity and with it, your senses. So be quick and accomplish your critical mission before it's too late and you become an undead.
Best experienced in Chrome. Controls: WASD, ZQSD and ARROWS to move. MOUSE to aim and shoot.