Although the Sports Comedy genre is often plagued with cliché and is usually only for the most strict of fans, you definitely don't have to be a Soccer/Football fan to enjoy Shaolin Soccer, It helps if you enjoy the idea of a silly (but not stupid or bad) Martial Arts Flick.
Compared to films of director Stephen Chow's past (King of Comedy, God of Cookery), Shaolin Soccer is a much greater visual treat. Although he's not exactly from brilliant yet, the direction has improved vastly. And the new CG scenes are often amusing and visually interesting demanding repetitive viewings.
While the film is fun and generally smart, it falls prey to a bit of an obvious story, of course this is one of those little-plot high-laugh comedies, One can't help be feel bogged down by some of the love plot, which unlike a lot of the soccer field action, it's totally predictable and at times is a bore.
If you must see Shaolin Soccer, be sure to watch it with it's original language and subtitles. The American English version had many of the films funniest scenes cut to make the film more PG-13 rating. Watch it in it's uncut version to see one of the funniest and most enjoyable Sports-Martial Arts-Comedy of the 2000's.