Ask HN: What are the best exercises for gathering input from a large group?

I am personally a big fan of Corinna Baldauf's "Retromat" (https://retromat.org/) which contains a ton of exercises/games for gathering and dealing with feedback. Exercises are designed for retrospective meetings, but I feel they're applicable to all kinds of feedback/brainstorming sessions. It's organised by meeting phases, so there's a rubric for "gather data" activities.