Take a little bit of Shanghai Noon, a little bit of Rush Hour, remove the oriental spice from the stew et viola! you've got I Spy! By mixing the essence of Jackie Chan's sidekicks from both these films and putting the resultant stew into a comedy spy movie you have this enjoyable if unspectacular film. Wilson does his usual stuff but is still effortlessly funny, Murphy does his best Chris Tucker impression and does a good job playing a little dumb and is funny as well.
The plot sees them doing, well, it doesn't really matter what they're doing, just that Wilson is Wilson and Murphy is playing up to good effect! The plot just about provides enough material to keep the film going, but the odd moment where the comedy banter quietens down, the weaknesses of the plot are immediately laid bare. This is not to say it isn't good enough for this type of film, but just that at times it is all very slight and a bit thin. The comedy is more based on banter than anything else, so if you like the two aforementioned Chan movies then this should be enjoyable as the humour is of the same vein.
The support cast are all pretty average. Janssen does an OK job looking pretty but Malcolm McDowell just shows his face to no great effect. The funniest cameo is Gary Cole who plays an Irish spy playing a Cuban he is just so unexpected in his actions that I had to be amused (of course he is helped by Wilson'' reactions to his character).
Overall this was kinda overlooked at the UK box office and I think it was because it was very slight and flimsy. However for gentle laughs based on good banter rather than set up jokes, this is a surprisingly fun comedy despite not sticking in your mind for longer than 15 minutes after you watch it.