How bad is it? It's one of the worse unfunny comedies of late.
Should you see it? No.
Apparently, British television produces films based on 10-minute sketches just like Saturday Night Live does in the U.S. I had never heard of the character of Keith Lemon, so I wasn't exactly the audience for this, but it's just a series of penis, boob and fart jokes - and not very funny ones. Keith invents an Apple-phone like "Lemon phone" and becomes super-rich and famous, only to lose it all. The film's reason for existence seems to be endless cameos by not-exactly-A-list celebrities, most of whom are unknown on this side of the Atlantic. Kelly Brook is in her underwear most of the film, which is a plus, and the others recognizable to most here are: Verne Troyer, David Hasselhoff and former Spice Girls Emma and Mel. C.