If the people participating don't know each other yet, setup a team matching / speed-dating-style activity where people can introduce themselves, and brainstorm

If the people participating don't know each other yet, setup a team matching / speed-dating-style activity where people can introduce themselves, and brainstorm and share ideas. Invite a few guest speakers and possibly organize some events (eg: yoga, snack time, improv exercises, video game break) to break up the monotony of everyone just staring at their screens. Setup a support staff / helpdesk queue with mentors (either more senior students or staff, or possibly volunteers from industry) to help out teams that get stuck. And make it easy to share contact info (eg: QR code badges which you can use to share email or chat information) for networking purposes.