You start with a infected character that tries to go as far as he can before he dies or infection takes him. You eventually die and repeat with new character. The game is fun and you feel progress as you advance. As you learn the game you get closer and closer to the end. The game mechanics is more or less ok as is but there is one big issue on my PC, and I see that I'm not alone. When I start the game it just does not start, I get stuck on the loading screen. Nothing helps but eventually after 10-20 attemts it finaly loads. This is the reason for 4 stars.