Lack of solid plot:
There is a very basic narrative to this movie, however there's never any plausible motives for any of the plot driving moments. In some cases there's no motive or explanation at all.
Visuals:
Poor CGI and visuals throughout which at times were laugh out loud ridiculous. Not much more to say on that, but the poor quality is distracting.
Bad acting:
Mostly of the acting is thoughtless, action film acting, so can't be faulted too much. It is part of the genre. However, you could sense the boredom, and awareness of the films cringeyness in the acting. Their hearts aren't in it. This is most obvious in Bruce Willis. A great actor on his day, but in this film seems to list off a bunch of cliché lines in a way that screams 'I know this film is terrible'. Can't blame a guy for wanting to make money, but it's sad how obvious it is that it's the only reason he's there.