We played that everything stopped the first time we played the challenge. Then in correspondence it was pointed out to me the rules reference's to "turn" so a HBTD roll would be required at the begining of each turn.
I don't think its very well worded and seems we are not the only one's to have fallen fall in to the "all action stops" preface trap.
By all other action pauses we concluded this means the exclusion of all other threats / events, but not the begining of the turn HBTD. going forward we shall play it this way...
How do you folks feel about the challenge. I have the Undead Gunslinger but have yet to be challenged. I have heard a review where the reviewer thought it did not work well and really stopped the pacing .