So yesterday, I was given both the hairball challenge (I can't remember what it was called) and the rainbow run challenge. Both times, I failed to do the challenge and failed to even figure out how to get out of the room.
With the hairball, I think the fail might be unique to me... there were other players there and they managed to get out. Whether or not they ever saw a hairball I don't know. I never saw one (I did pick up an object of no apparent intrinsic value and talk to a dust bunny). I'm not sure what was supposed to happen in that room, but I never figured it out. Everyone else left and I felt like I'd tried everything I could think of. I couldn't figure out how to get out, but I still had the other challenge available, so I went there.
And I think this was a bug, but the timer never seemed to start for the rainbow run and then also I couldn't figure out how to get out, but I followed stoot. (And then, as I mentioned elsewhere, the rainbow run timer displayed in my window never went away, not even after a few restarts.)
I'm not sure what might have been bug and what might have been feature (and personal fail) here... but I also thought I should be able to (get out when I'm tired of trying and) go back and try again after giving up on these special tasks.