[serf]

Feynman worked on parallelism with a team of other scientists ranging in ages, he just happened to be put as head of the 'IBM Group' which had been tasked with yield calculations at that time. It's unfair to say he alone invented parallelism, which is sadly becoming the popular opinion.

I don't know enough about the other feats to comment on them.

It's way impressive how young Feynman was when he was apart of the whole project, though. He was the youngest member.

[abraxasz]

Let me quote an excerpt from Surely You're Joking, Mr Feynman (p. 127 from my edition): "... I had a very good group [..] clever boys from high school who had an engineering ability". So yes, it was a team of people, but those working on this specific problem seem to have been high schoolers or recently graduated kids :)