There are some great achievements for dying, and dying is pretty easy to do. But there don't appear to be any achievements for living (not that I've seen, that is).
For those of us who, by design or fluke, manage to avoid squishing in hell, it'd be great to have an achievement tree to mark our efforts.
I've made it a personal goal to stay outta hell for as long as I can. So I propose a disco ball-themed achievement for stayin' alive! Level 23 and counting!