An alienating mayhem!
Because predator is a horror movie strongly inspired by creature films from the realms of science-fiction and action, it presents protagonists with caricatural courage, big muscles, big guns and bad tempers rather than frail individuals. Arnold Schwarzenegger is, as usual, a man of few words. His stoic presence is all we need. The rest of the cast is also rather purposely downplayed.
The first act would have you think this is a war movie, but then greatness ensues... Predator is all about the alien, really, and what a great creature design we're treated with! The effects aren't always crisp and photographically seamless, but they bring something new to the audience. The jungle is a character of its own. The whole film is spent there and the makers make the most of it.
Although Predator could rightfully be labeled "slasher", it mostly bathes in a heroic military score that keeps us away from a clichéd victimization of the cast. The structure isn't unlike that of most action-thriller movies of the time. Well shot, frantically paced and skillfully directed, this is an instant classic that was allocated the big budget its premise deserved.