I had no idea what to expect. I believed the people who said it was just a bad movie, but I have to say this is the most genuine Indiana Jones movie of the series. I know I know, a contradictory comment to most reviews on here, but I really believe this is the kind of movie the series always aspired to become.
Spielberg intended for Indiana Jones and his adventures to be serial stories. He wanted to play into the stories of the 1940s comics. The adventures would be over the top and the dramatics would mix humor with heroics. The stories would be believed in because the combination of both elements wondered the basic imaginations of children. Raiders of the Lost Ark was a general adaptation of the old comic book formula. The tone was quasi serious mixed with a little humor. It made children ooh and awe and adults to return to their childhood, but Spielberg had nowhere to go after that movie but to become more comedic. To get more serious would have took the fun out of the franchise. As an adult he knew the old serial stories were basic pieces of entertainment so he developed the series to encompass more realms of entertainment and comedy. The Last Crusade may have caricature versions of the original characters, but those original character were already old stock adventure types.
The action and adventures in the new one is random and all over the place, but what Indiana Jones movie doesn't have that. The character is the American James Bond. The films aren't meant to be strict stories of adventure set in one locale, but world wide adventures that have exotic and mythical lands as common back drops. I thought one of the pluses of the series was its ability to cram numerous action sequences into any place. Last Crusade has one sequence that begins in a library, goes through tunnels and ends with a boat chase. It's also just an early adventure in the film before later, greater ones. Random has always been the description of the action sequences in the series. The best part about the action sequences in Crystal Skull is that they still have some little bits of character drama within them. In Last Crusade Henry Jones Sr. and Marcus Brody were feeling the bond of reuniting all while fighting bad guys in a tank. In Crystal Skull Indiana first learns and develops bond with his son during chase and rescue sequences. It's a continuation of an earlier development in the series.
The best development is the constant injections of 1950s culture in the movie. Old serials are important today because they are cultural markers of a different time period. Music critic David Hajdu went deep into comic book cultural lore with his new book, but most modern looks at old serial stories make sure to inject as many societal hat tips as possible. From Mutt sparking a greaser/jock fight to the injections of Alien life (and Roswell, too!) all over the story, the movie has numerous markers about the 1950s. Indiana Jones even wanders into an old desert testing town for atomic explosions. The only hat tips to the 1940s in the other movies was the Nazis and wardrobe. The stories were mainly generic adventure stories, but Crystal Skill better fits the realm of most modern serial odes with its consideration of the 1950s culture. Spielberg set up the entire film to be an ode to a by gone era. It's only fitting that he makes the film decorated with as many cultural pieces as possible.
All of this being said, I'm not the biggest fan of the series. Harrison Ford has his most appealing character with Indiana Jones, but I always have known funner films and better action characters. I re watched the series again recently and was happy I could enjoy it, but I didn't seem to enjoy this one more than the other ones. Last Crusade is still a personal favorite, but I'm at least happy with the progress Spielberg has put into the movie. I wouldn't really recommend the movie to anyone. Iron Man is still tops as far entertainment for the summer goes. This movie was just a good curiosity.