Some suggestions:
Add 'in progress'/'started' as a project status. This would affect some other features as well, for example filtering the project list. But it would allow people to find new projects more efficiently.
Also add a field for 'time to finish' once the project is done.
Allow sorting or filtering projects by est. time. If I don't have more than 4 hours, I don't want to see any projects that take longer. Additionally, in the 'New Here' section: Clusterify: work on fun, small (~2hr) projects and meet other coders. '2hr projects' is not very relevant - a lot of projects listed are est. time >2 hours, and it really depends on the quality/quantity of people who join.
Do you want to explicitly specify a limit on the number of people who join? Once the limit is reached the project can move to 'In Progress' status. The project submitter can approve join requests.