I’ve always found Patch Adams to be two movies in one. The first is a comedy story about the offbeat physician pissing off the hospital administrator, while bringing joy to the children in the hospital. The second is a drama about an disturbed adult patient who snaps one day.
Either, filled out, would have made a good film. But joined together, they don’t really work.
Robin Williams always struck me as somebody who should do comedy throughout a film (Moscow on the Hudson, RV), or drama throughout a film (Awakenings), but not films where his comedic style is presented in the first part, but the second discards that in favour of a more dramatic style. Good Morning Vietnam is another example of this “comedy first, drama next” style.