Simon Cowell's The X Factor musical has impressed critics who have hailed the satirical show as "smart," "funny" and "bonkers".

Reality Tv spoof I Can't Sing!, which has been bankrolled by The X Factor creator Cowell, has suffered numerous setbacks over the last few weeks as producers struggled to correct a slew of technical problems, but it opened as scheduled at the London Palladium on Wednesday night (26Mar14).

The show went off without a hitch and won over theatre reviewers, who were full of praise for comedian Harry Hill's script and Downton Abbey actor Nigel Harman, who plays a role spoofing Cowell.

Paul Taylor of The Independent newspaper described Harman's performance as "deliciously funny", adding, "A satire on The X Factor that's been endorsed and partly financed by Simon Cowell sounds an improbable proposition... So it's with some surprise that I must confess to having really rather enjoyed this £6m (million) musical spoof... There is a bonkers, surreal charm to the loopy lampooning."

The Daily Express' Simon Edge praised the show as "smart, funny, foot-tapping and surprisingly hard-hitting" and even compared it to acclaimed stage show Jerry Springer: The Opera, which lampooned the controversial U.S. Tv star.

Charles Spencer of The Daily Telegraph also gave the production a good write-up, calling the show a "rude and raucous hit".

He adds, "The show is wildly eccentric and wonderfully funny. It is also splendidly rude about Cowell himself... It's not exactly West Side Story, but the performers give it all they've got, the designs are spectacular and the whole delightfully bonkers show has a winning wit and warmth about it."

Cowell was in the audience for the opening night show along with his girlfriend, Lauren Silverman.