I'm assuming the hackathon had more stuff besides just coding. Pay attention to that other stuff. Meetings, interviews, final presentation, etc. Opportunities to demonstrate soft skills (communication, team work) matter heavily. For the actual app, a super great app is nice, but remember the hackathon is also about the experience.

If people don't know how to do stuff, offer to teach them. Give them a small part that is within their skill level. If nothing else, at least communicate heavily about what you're doing. If your team can't create the app you all thought you could, that's a great opportunity to learn to scale back. Knowing when to continue and when to change course is a very useful skill and would be a great situation to talk about in an interview. "Once we realized we couldn't do everything, I went through the plan and prioritized which features were most important and doable based on our skill level" shows good problem solving abilities and how you helped your team. "Once we realized we couldn't do everything, I didn't sleep for 2 days and did the entire project by myself" does not make you sound like a teammate.