First Hit: Although they bend time, in both dialogue and thematic stories, there are some funny bits but for the most part the joke gets old quick.
The film begins somewhere around the caveman days with hunting and gathering being how everyone's days are spent.
Jack Black (playing Zed) and Michael Cera (playing Oh) are best friends and have opposing personality types. Zed is obvious, outgoing and a loud optimist while Oh is the cautious, introverted and unsure one of the two. Their personalities work fairly well together during the film when a scene is set up well. Like when Oh wants to dance with the girl of his dreams in an early sequence.
Each are outsiders in their current village so when Jack makes a mistake and spears the village big shot, they are asked to leave the village. The two head off together to create a new better, more exciting village. Hiking over a mountain, they discover they won't fall off the end of the earth but end up thousands of years later running into Cain and Abel. They meet these brothers just in time to witness Abel's death by Cain.
Then, just as magically, they are whisked to Egyptian times where they are slaves about to be stoned to death. Fancy talking by Zed and Oh, who has gained new strength because of first sexual experience, lift themselves out of their dire predicament and into a happily every after ending.
There are some funny moments in the film and others that were meant to be funny but landed with a thud (think hairy chest massage, it just wasn't funny).
Black is Black, a loud, smart aleck con-man, which as I said before, plays well off of Cera the thoughtful cautionary. There are moments that their skills work intelligently off each other, but mostly this is a sophomoric mess held together mostly by Harold Ramis’ reputation.
Overall: Not worth seeing except as a video on a very lazy rainy afternoon with nothing else to do.