This movie starts out with a tone which makes you think it is a fairly serious film about a young man dealing with the consequences of being raised in a fallout shelter. Then, at the point where he goes up to the surface, it turns into some screwball summertime comedy. I hate when movies do that.
There are probably lots of good serious films out there that deal with the theme of adjusting to the real world, such as films about coming out of prison after years of serving a sentence for a crime of which one was not guilty, or films about people coming out of cults. Perhaps maybe "Room" does justice to this theme.