Good watch, might watch again, and take it or leave it: it's just nothing special.
Now, I like Jason Mantzoukas (The League, The Good Place, Brooklyn 99), he does crazy like no one else, but Tony Revolori (Spider-Man: Flash) is kind of the character to carry the movie, but he's playing a slightly more sensitive Flash Thompson, with moneybag parents, and part of the premise is that Richard has give Nat a taste of real life on this road trip so the character is literally designed not to be equipped to carry the movie in which he is designed to carry the movie.
I think if they had fixed that problem this would have gone from okay to awesome. There is a lot of good humor in this, they could have expanded a couple of the scenes and upped the "this is so crazy" factor a little bit (see Search Party): it is almost like they or the studio were afraid, or they had to embody the fear of their protagonist in their approach.
There are a lot of good things here, and I like a good roadtrip movie, there was just a lot of room for improvement.