It starts with the most copied scene in the history of this genre. I call it "Who are these people and why are they fighting?" Then it gets crazy nuts and that is a good thing.
This is an action comedy best summed up by Melvin's line "This is 1981, pal". Many of the jokes are cultural references that died decades ago. Plus there are the jokes that just do not translate. What's left is the slapstick and sight gags and insider jokes if you are familiar with this genre. Despite those limitations I still did get a kick out of this movie.
I would rate it average and recommend it only if you have previous experience with this type of movie otherwise you wouldn't get it and that is never funny.