If you're a massive fan of the first four "canon" films (like me) the best way to approach this film is to say to yourself this is a separate thing. It's easy to do so, as apart from a few nods to previous events, this film has sod all to connect it to the canon. The script is dreadful, and the cast make a game attempt to do their best with it, but this isn't what most people come to this film for. The action sequences are excellent, especially the first fight between Xeno and Predator which is pretty jaw dropping, and the plot (what there is of it) is silly and enjoyable - there's plenty of decent stuff going on, right up to the incredibly violent climax, and you can always play "Spot The Plot Hole" if you DO get a bit bored. That will keep you busy.
You can see why people who love the canon films hate this so much - it's pretty brainless, and it lacks so many of the things the other four have. There's too little of the bone-freezing horror of "Alien", none of the superb character development that made "Aliens" such a huge hit with audiences, not enough of the chilling echoey industrial art-terror of "Alien 3", and none of the gorehouse comedy and atavistic dread from "Resurrection". Give your brain the night off, and you'll really enjoy this.
You can see why people who love the canon films hate this so much - it's pretty brainless, and it lacks so many of the things the other four have. There's too little of the bone-freezing horror of "Alien", none of the superb character development that made "Aliens" such a huge hit with audiences, not enough of the chilling echoey industrial art-terror of "Alien 3", and none of the gorehouse comedy and atavistic dread from "Resurrection". Give your brain the night off, and you'll really enjoy this.