I'm not going to say this was a great movie. I found it entertaining the same way I would an amusement park ride, but the plot is even thinner than the other movies, and Lisa was so irritated with the internal inconsistencies that she said were she watching it by herself, she would have walked out on it.
On the way home, she came up with what she thinks would have been a better ending, and one that's more in keeping with the original film, too. Bringing all thirteen crystal skulls into the right configuration triggers off an apocalypse in this movie. But instead of what actually happens, Lisa suggests that we have the big destructive scene, with all the bad guys getting what they deserve, and the good guys coming to on a broken-up plain with the thirteen skulls scattered about, no longer in the "death and destruction" configuration.
One of the characters -- Lisa suggests "Mutt" -- says, "Do you think that could happen again if the skulls ever were put back in that formation?"
Marion says, "We've got to keep that from happening!
Ox says, "But how? These skulls are indestructible!"
Indy looks up and says, "I've got an idea."
CUT TO a quick sequence of shots of individual skulls, boxed up in the same way as the Ark was in Raiders. One of the boxes goes into the repaired Nevada warehouse. Then another goes into the Vatican archives. Then another into a Tibetan monastery. Another into an obviously British safe hiding place. Insert a shot of Ayers Rock. Then a submarine shooting something from a torpedo tube. And so forth, obviously implying that the things are being scattered to the winds to keep them from being reconfigured again, with each of them in a safe and (we hope) hidden location.
I really like her ending better, because I think it evokes the original Raiders of the Lost Ark -- and besides, it also sort of explains how Indy manages to repair his reputation. As it stands, the final scene assumes "Come home, Professor Jones, all is forgiven" without really establishing even with a single throwaway line how that happens.