This was so bad it's downright embarrassing.

0/10.

Why would these two characters ever go out on a camping trip together? They don't like each other and it's not as if they have some plan on what they are going to do out in the wild...

They are just too unpleasant to feel anything for, you sort of just want them to die to make the film shorter. Much shorter.

The filming is low budget, which can be real good sometimes, but the fighting scenes are so badly done that there is nothing to it more than just fill-out.

I used to love watching survival man before he started to claim that he was the only "real" one out there, which is just bitterness, and I guess he is trying to make some money out of his old fame, but he is no actor, in my never humble opinion. (see, I am like him in that way)

But what really makes this movie bad is that they're just not likable at all.

This is a very low budget affair. With three cast members and a dog, and it's all shot in one location. It's also darker and more crude in tone than I expected, and it gets a little crazy near the end. There seems to be a script for the dialogue, but some of the lines and scenes feel ad libbed. It could also just be an issue with the editing, because lines of dialogue are being repeated after camera cuts.

Most of the exposition of the two primary characters is done through flashbacks. Though they do provide context for their relationship and history together, they could be cut entirely from the film. The scenes are jarring, and visually unpleasant due to camera focus, and after effects. These scenes are bloated and unnecessary, and the exposition added could have been delivered in more effectively ways.

The movie does make a clear distinction between a cenote and a sinkhole. With a cenote being formed in limestone, so you know the characters are surrounded by stone, and not soil. Which means they can't just dig themselves out. The issue is a real lack of continuity and establishing shots of the cenote size and depth. It's hard to get invested in characters, if you can't appreciate the situation they're in.

By far, the most perplexing issue with the film is seeing some really poor survival techniques on display. The twist ending maybe an excuse for these issues, but it still doesn't actually work narratively. When you have the Survivorman playing the lead, you don't expect bad survival practices.

A few such issues, without really going into spoilers is being severely pierced by an object, and pulling that object out of the wound. Using fire to cauterize a wound (this is one of those dangerous tropes),and the treatment used for a bite that is fatal in less than 1 in 1,000 occurrences.

The ending was a real disappointment too. This type of twist ending is one of the worst tropes in all of film and television. Without spoiling anything, this trope is a slap in the face of an audience, saying this was all a waste of time.