This is bonkers... and I thoroughly had fun with it!
I will say that the ending is very underwhelming, like what was that?, but I still had an entertaining time with 'Santa’s Slay'. Not all the jokes land, naturally, but the ultra menace and violence that ensues with Santa is great to watch, I can't lie. It is violent ('only' rated 15 on Prime UK, mind) so beware of that if that isn't something that floats your boat.
Bill Goldberg is brilliant casting as the big, red dressed figure. He nailed and absolutely looked the part - great character. Those behind Goldberg aren't as strong, though Douglas Smith, Emilie de Ravin and Robert Culp are all more than satisfactory. I also quite like the effects, not that they are anything extraordinary but it all works; aside from one scene, I can't recall exactly which one so I guess it can't have been that bad.
I did notice one or two bits of dodgy ADR and, as already noted, the conclusion is a tad disappointing. Still, all that precedes more than makes up for it to be honest.