Create a big scale (i.e. a long line) on the floor with masking tape. Mark one end as 'Great' and the other as 'Bad'. Let participants stand on the scale according to their satisfaction with the last iteration. Psychologically, taking a stand physically is different from just saying something. It's more 'real'. You can reuse the scale if you close with activity #44.
This is a round-based activity. In each round you ask the team a question, they write down their answers (gives everyone time to think) and then read them out to the others. Questions proposed for Software Development teams:
When was the last time you were really engaged / animated / productive? What did you do? What had happened? How did it feel?
From an application-/code-perspective: What is the awesomest stuff you've built together? What makes it great?
Of the things you built for this company, which has the most value? Why?
When did you work best with the Product Owner? What was good about it?
When was your collaboration best?
What was your most valuable contribution to the developer community (of this company)? How did you do it?
Leave your modesty at the door: What is the most valuable skill / character trait you contribute to the team? Examples?
What is your team's most important trait? What sets you apart?
('Remember the Future' (#37) works well as the next step.)
Find the source of problems whose origins are hard to pinpoint and lead to endless discussion Source: Henrik Kniberg
Write the problem you want to explore on a sticky note and put it in the middle of a whiteboard. Find out why that is a problem by repeatedly asking 'So what?'. Find out the root causes by repeatedly asking 'Why (does this happen)?' Document your findings by writing more stickies and showing causal relations with arrows. Each sticky can have more than one reason and more than one consequence Vicious circles are usually good starting points for actions. If you can break their bad influence, you can gain a lot.
If your team has a tendency to see obstacles outside of their team and influence and primarily wants others to change, you can try this activity:
Draw a big rectangle on the board and another rectangle inside of it, like a picture frame. Hang all complaints and grievances that surfaced in previous phases into the frame.
Now comes the interesting twist: Explain that if they want anything in the outside frame to change, they will have to do something themselves to affect that change. Ask the team to come up with actions they can do. Put these actions into the inner rectangle (near the outer sticky they are addressing).
Gauge participants' satisfaction with the retro in minimum time using smilies Source: Boeffi
Draw a ':)', ':|', and ':(' on a sheet of paper and tape it against the door. When ending the retrospective, ask your participants to mark their satisfaction with the session with an 'x' below the applicable smily.