Hmm i have a basic idea for a mod. Though i'm not sure how much work it would be but basically it's a timed dimension...
You build a portal in which you are transported to a random location in the dimension, and have your exp decrease each tick. When your exp reaches 0 you are transported back to the overworld.
That's all i can think of for now xD
Though if you guys can help me expand on this that would be awesome
Since i'm not really sure what the limitations of making a mod is, i can't really give a more properly expanded mod.. >.<