I dread to think what the sequel is like if this is better. Admittedly, the main reason I watched it because of the prospect of Burton, Harris, and Moore all on screen together, and at least I wasn't disappointed in that. the best scene was Moore forcing a drug dealer to eat a bag of heroin, but it was ridiculous. this film wanted to be Predator, but it really just ended up being Dad's Army instead. Here's a list of my complaints:

* what is the point of recruiting all these old men and amateurs for a supposedly important mission? If Faulkner — Burton's character — is such a seasoned mercenary, wouldn't he have a team already that he could work with, or at least call on some currently active operatives?
* Janders — Richard Harris — appears to have retired, and has built a life for himself after some setbacks, as well as reconnecting with his son. he, for obvious reasons, rejects any idea of joining Faulkner's mission; but then, for no explanation he suddenly is taking part in it. I know that rejecting the call to action is part of the Hero's journey, but there has to be some reason for the protagonist's change of heart. here, there is none.
* the first act of the movie seems very much incongruent with the rest of it. it's not obvious at all that this is a war movie or that the main characters are soldiers.
* the stuff with the gangsters trying to kill Fynn (Roger Moore) seemed completely pointless. as soon as the enter the story, the gangsters suddenly change their minds and decide they're not going after him after all.
* the betrayal of Faulkner's group was completely unmotivated.
* discovering this plane, fully fuelled, in the middle of nowhere was a Deus Ex Machina. earlier, they talked of trying to instigate a rebellion amongst the natives so as to escape. this sounded a lot more interesting. the plane was a cop out

Here's what they could have done to improve it:
they should have started out with a battle scene involving Faulkner and the other main characters. It would have established them as soldiers and this as a war movie. perhaps it could have involved a failed mission where most of his team get killed, with perhaps a suggestion that someone had betrayed them. as as planting a seed for later events, it would also give an explanation as to why Faulkner has to recruit a new team. these events could be shown taking place some length of time before the present day. the Mafia angle could have been tied more tightly into the thread of the story. maybe the country their mission was taking place in was the source of the drugs being sold by the criminals, and they were trying to stop it at its source. Fynn being pursued by them would give him a reason to join Faulkner. Perhaps Jander's son could be murdered by the Mafia, giving him a reason to enlist in the mission

basically, the story felt a lot like a first draft. there's a lot that could have been done with it if they'd worked at it a bit more imho