This one is called Sprint Timeline helps individuals refresh their memories and build a collective story of the sprint.
Use a masking tape depicting a timeline. Couple of meters is a good size for a two-week sprint.
Then ask everyone to write silently for few minutes on post-its: I ask to think of the events that happened within the sprint and are important to be remembered. Anything goes here: parties, sick leaves, releases, meetings, conflicts, surprises. One event per a post-it.
After writing is done, ask people to come up one by one and tell their stories by sticking their post-its chronologically. You may want to limit time per person. Say to 1 or 2 minutes.
Additionally, ask people to draw smileys on the post-its represent- ing the emotional state of the events.
That also works great for longer time-slices, like for instance quarterly releases. Actually, the longer the period being retrospected, the better this tool works.
Once the collective memory is there it is so much easier to get a deeper dive into specifics of the previous sprint with activities like Sprint Perfection Game, Working Well - Needs Fixing or More-Less-Keep-Stop-Start.
See the the Retrospective Cheat Sheet for more details on these exercises.
Retrospective Kickstarter Plus A Cheat Sheet
"Sprint Timeline" is one of the 16 powerful exercises that I've been using most often facilitating different retrospectives: from a single team looking back one sprint to a multi-team group retrospecting a whole many-month release.
Combining these 16 exercises is giving you more than 250 different agendas (should be enough for the next few years!) - so go and get the Retrospective Cheat Sheet together with
a mini-book Agile Retrospective
Kickstarter that helps you get prepared for your next