Missed approach/go round - yes make a PA.
Humour - No. Enough people will be of the "we climbed vertically and I thought I was gonna die" mind set that humour is no appropriate. Also one assumes the workload will be high enough, depending on a/c type and other traffic, that there won't be time for jokes.
What to say - Basic reason (generalisation only) for go round. No need for concern. Expected landing time.