Sylvester Stallone built a lot of goodwill 13 months ago when he returned to his “Rocky” roots, but that may all be evaporated with his latest time warp project “Rambo,” an unintentionally hilarious comedy disguised as a bloodbath action film.

This latest installment featuring the reclusive Vietnam vet is like watching a late night rerun of an ’80s action movie – the only difference is that the gore quotient has risen exponentially. It’s so retro I half expected Chuck Norris to make an appearance as his Braddock character from the “Missing in Action” movies.

This story begins with John Rambo (Stallone) withdrawn from society and leading a simple life in Bangkok, doing what everyone else would do, rounding up snakes and fishing with a bow and arrow.

Rambo is approached by a group of Christian missionaries, looking to rent his boat to travel up river to war-ravaged Burma.

At first Rambo is reluctant, but he is eventually convinced by a young woman (Julie Benz) in the group.

After getting them safely up river, Rambo returns to Bangkok. But he soon learns the missionaries have been taken hostage by Burmese soldiers and agrees to help a team of mercenaries rescue the surviving relief workers.

The plot is really just a diversion for the real purpose of “Rambo,” which is to find a way for Stallone to revive his sagging career as an action star. The movie doesn’t quite succeed in that regard, but I have to say it did entertain me to a certain extent.

The action sequences are beyond absurd, with heads exploding like watermelons and body parts flying all over the place. There is so much death and carnage that my friend who watched the movie with me suggested they put up a running tally of how many people were killed at the bottom of the screen. (If they did, that ticker would be running like an odometer).

The acting is just as laughable, with Stallone barely speaking (which is actually a good thing) and Benz looking like a poor man’s Laura Linney.

Stallone tries to throw a message into “Rambo,” but even that attempt at drama results in laughs. It’s too bad Stallone didn’t realize how funny this was while he was making it, because this had the potential to be comedic gold.

Instead, it’s just another example of why January is usually the worst month of the year for moviegoers.