I went to a social gathering of former co-workers using Gather.Town. Each person has an avatar which they walk around a 2-dimensional map. You see video (and audio) of everyone within a certain distance, and apparently if you’re in a “conference room” you see everyone in there. It did replicate the behavior of in-person parties where you groups would form, and people would join them or break off to find a new group. It was far better for the purpose than trying a Zoom call with 50 people, where there’s a single awkward conversation.

Some of the user interface was confusing as a first-time user, but overall it was effective and people wanted to do it again.