This film started promisingly, and for about the first 35 minutes was full of riotously funny humour - but then, it appears that the scriptwriters just ran out of the ideas - So what did they do? They just repeated the same old ones over and over and over again to the point of tedium, where you can see the jokes long before they arrive.
A pretty girl walks past Kevin and Perry - and you just wait for one of them to get an erection for the hundredth time - the same joke was done better in Waynes World (schhhhwing!). A few laughs are saved for the last 5 minutes or so, but this just looked like a what would have been funny as a 30 minute TV show, padded and stretched into a movie.
In the UK, this film has been rated '15', which is a shame as a sizeable proportion of the audience that would most likely appreciate the schoolboy humour is too young to see it at the cinema - They'll probably catch it on TV sooner or later, which is where this film belongs.