Something of a disappointment coming from Ricky Gervais, but an entertaining enough comedy. The cast is likable, and there's a slew of celebrity cameos and clever moments, several of them inspired and hilarious. But it never quite reaches its potential, the plot especially goes soft and looses its way toward the end. Worth watching, but nothing all that special.
The premise is a pretty interesting setup for a good comedy, and for the first part of the film it works very well. However, Gervais ruins it by using the latter half as a smug and hamfisted anti-religion spiel.