The myth of Radfall

You were born and raised on the underground, youve heard a lot of stories about the outside and how isnt the place that once was habitable, all the people are comfortable with his current life and they really think that this underground is their world, and all who get out dont come back, but anyways you want to see it with your own eyes. They say that out there are dangerous beings and you cant even breath more than 5 minutes, but will that be true? Welcome to my first post-apocalyptic prototype...