Three major faults - Nate, tone and the structure (spoiler)

After the first 15 minutes I knew why the movie bombed. After the first hour, I knew whose fault it was.

The guy playing Nate is made out of cardboard and pairing him up with acting legend like Tommy Lee just made it more obvious.

The tone of the movie is all over the place. First it's a swashbuckling adventure, then it's massacre, slavery and gore, then we're back to swashbuckling and so forth. Indy 2 made one of the heaviest themes out there like child slavery fit like a glove in a fun adventure movie. They couldn't catch that serious but tongue in cheek tone here and the tonal shifts are just jarring to me.

Finally, the framing story was forced into the real story even though they had a perfectly fine complete tale in their hands in the first place. That completely unnecessary introductory scene is very jarring since they pretty much kill off the whole bloody crew and Jones running away cheerfully while his whole crew ends up caught or dead doesn't really spell hero (or antihero for that matter). Of course we don't really know what happened to them, 'cause the movie never mentions it again! And the ending sequence is improbable, kind of stupid and unoriginal and it's a much much less climactic than the explosion in the scene before this one. Even if these two scenes were part of the original storyline there was no need to jump around in the timeline .