Does this work for just 2 people?

Yes and some 3 people you can somehow manage to pass with only two, but it's much better to have 3 people at least.

There are some games that require at least 3, so you may not be able to do all 16 games but there are some specifically designed for 2 players (can be done with more).

I would say 3 is a good minimum. But I think there are a few rooms you can do with just 2

Some of the rooms yes but most of them need 3 or more.

Different rooms require a different minimum number of people. We went with 3 and were able to try out most of the rooms, but there were a few that required 4 if I remember. There were a good amount with 2 as the minimum, so it will work and you'll have plenty of fun - you'll just be more limited in which rooms you can try.

Yes but some of the games require 3 - 4 people. So 3 - 4 are better.

Yes.