Hi nutmegger1,
Our D has similar interests and traits - interested in math/music/computer science, doesn’t find fun in sports or the typical party/drinking scene, very much enjoys performing arts. She also doesn’t use social media, loves video games, is mature but very down-to-earth and simple.
As others have suggested, Swarthmore came to mind for your son. My impression is that a lot of mature students find a nice home there.
Case Western is also on our list as it seems to attract a similar type of student. We haven’t visited yet but I’m hoping we like it when we do.
One last thought is Clark University in Worchester, Ma. Someone here suggested it. D looked it up and likes that it seems low key and offers video game design (that’s a separate topic but I’m excited that she’s excited about creating her list! lol). I read that there are lots of research opportunities at Clark for undergrads to work with graduate students and professors. So if your son prefers the company of adults, this could be an aspect that may appeal to him. They also offer merit aid.
I’m sure many of us would be interested to hear which schools he prefers if you are inclined to share. Best of luck to you both!