A guy dies and goes to heaven. I remember he goes up in a cart and then ot stops infront of a bunch of cartoon characters. Then the movie starts getting weird and there are strange black and white scenes where weird stuff is happening like an eye geting cut open.
Monkeybone (2001)
https://www.imdb.com/title/tt0166276/
That sounds kind of like “Cool World” to me.
https://www.imdb.com/title/tt0104009/?ref_=fn_al_tt_1