The short version: it's stupid.

The long version: it's a bigger and wackier remake of Escape from New York.

That's pretty much all there is to say about it. It has a shocking amount of recycled story beats from the first film, the villain is lame and forgettable, the comedic sidekicks are useless, the plot is slightly hard to follow and the CGI is very questionable. Granted, it's better than I thought it was going to be, seeing how I've heard nothing but bad things over the years and since I didn't like the first one to begin with (maybe a rewatch is in order). Escape from New York at least took itself more seriously and had a pretty cool atmosphere, despite its bad acting, underdeveloped characters, lackluster plot and equally forgettable villain. It's more entertaining than The Fog and it's definitely better than Ghosts of Mars and The Ward, but it's still a pointless sequel / pseudo-remake that's in the lower tiers of Carpenter's filmography.