Hmmm, actually sounds interesting, but I think that eventually I'd get irritated for not having a definite end that I have to reach :P

Also, I'm really not a fan of timed stuff, aka 30 min per run or so :| Too much of it already and the feeling of being rushed is really starting to get on my nerves. Sometimes I just wanna progress slowly and enjoy the scenery while being splashed by monster blood.