Arielrocks5’s review published on Letterboxd :
You know.....this ALMOST works.
It's got the color, it's got the production design, and it even has some good action (well...in concept anyway, but I'll get more into that in a second), but the problem with it is that it feels rather...unpolished, I guess is the word I'd use? Like it doesn't feel finished, as if it needed another quick haul at the effects section before being put in theaters but they had to rush it out as soon as possible, making each time there's a digital effect on screen look distracting.
Oh and speaking of distracting, why the hell is Matt Damon even in this? The most his character contributes to the plot is looking at the cool stuff this army on the Great Wall can do and saving a couple of lone solders in dire need of it, but not only does Damon look bored as fuck, there's really no reason for it to be him in the first place.
All you'd have to do is recast him and his stupid friend and it would still be the same movie, except now you bring up some touchy subjects about White Actors being in big blockbusters latched in Asian media of some kind (see also this year's equally mediocre and problematic "Ghost in The Shell").
But even aside from that, it's just a boring waste of time aside from a couple neat looking costumes and action sequences that would probably be more entertaining if they didn't look like so much ass.....