There's a very important political message embedded in Rambo. Something so important, that Sylvester Stallone felt the need to put his 80s era action icon into the Lazarus Pit and send him back into action. So it's kind of a shame that I have no idea what that message is aside from "war is hell" and "things are really messed up in Myanmar right now." All I got out of Rambo was an exercise in things and people exploding. But oh my! How they exploded!
We're reintroduced to the noticeably older (and absurdly buff) Vietnam vet as he makes his living as a snake-rangler and boatman. He reluctantly gets talked into escorting an incredibly annoying band of missionaries (it's the attractive and absurdly earnest hot blonde doctor that suckers Rambo in, pseudo-romance fans) down river to assist a village of less fortunate Burmese people. Sure enough Rambo guides them to their destination (not before killing a band of river pirates that are found of raping white women), and as soon as he leaves the village gets taken over by the Burmese Army. Taken over is a bit of an understatement, as the missionaries are captured, heads (plural!) get exploded, babies are stabbed and for the most part villagers get slaughtered in gag-inducing fashion. Even seasoned gore aficionados might feel queasy as most of the visuals tend to resemble a bag of meat being run through a woodchipper.
It's at this point the plot has chugged along enough to send Rambo back to the village to rescue the missionaries, save the village and spend time with a colourful band of mercenaries that have apparently joined the crusade straight out of central casting (the money-driven cynic! the book-lovin' idealist! the noble minority! Collect them all!). With much gusto, Rambo returns to stab, shoot and pummel everyone's guts out. As far as big dumb action flicks go, this is as big, dumb and action-y as the genre gets, so it's all in good fun. There's an absurd level of art that goes into blowing bodies with a machine gun or establishing just the right amount of emphasis on a throat being ripped out, and Stallone has it down to a science.
If you make the appropriate trade-offs (needless violence comes first and the plot is secondary), Rambo will cater to your kablammo! style action needs. Provided you have a strong stomach and thoroughly enjoy things blowing up.