I thought it was okayish; it's a popcorn flick for sure, then again I like dragons and unfortunately beggars have to be choosers when it comes to good dragon related media, especially film/tv.
>keeping it /k/ related
IIRC a lot of the collapse of society in the film was caused by governments having the bright idea to nuke themselves to kill the dergs, which went about as well as expected. The dergs in this film are non-magical (big lizzers with hypergolic saliva type) so they aren't equipped with RWR so any kind of radar guided missile will eat their lunch. The whole thing kicks off in London so I could definitely see them wreaking havoc in Bongland for a bit until the RAF (and USAF stationed in the UK, probably a bit of help from Adl'A from Fance) could get organized.