This is desperately poor stuff, juvenile in the extreme, thoroughly unfunny, and pitched squarely at younger kids. However, even they will probably find it too long and convoluted.
This is one of those British family comedies that make you want to soil the Union flag with your own faeces in the cinema foyer before setting fire to it.
A manic, mindless festive farrago that displays a casual regard for logic, stops every second for a bit of a song or dance and maintains an idiotic grin on its face through an interminable two hours.