I don't know if this one would be nearly as good in 2-D. These filmmakers understand why audiences have put on the 3-D glasses, and they offer up visual trick after visual trick in hopes of keeping the viewers wowed.
The plot is simple. Brendan Fraser plays Trevor Anderson, a volcanic scientist whose brother went missing during fieldwork. Trevor agrees to have his troubled young nephew Sean (Josh Hutcherson) stay with him for a week, but as soon as the kid arrives, suspicious activity is found on Trevor's computerized volcano-watch system. He and the kid pack up and head for Iceland, where they hire a tour guide named Hanna (Anita Briem) to lead them to the base of a volcano. There, Trevor finds what he always suspected: that there are volcanic tubes plunging straight into the Earth's core.
The trio falls down one of these tunnels and discovers a little "world within the world." There are mountains and an ocean, and other more dangerous things like dinosaurs, carnivorous plants, and man-eating fish. Together, they must navigate all these dangers and find a way to safely return to the surface.
Knowing that two-thirds of American cinemas will show this movie in standard 2-D, which is kind of sad considering that the whole thing exists as a demonstration of how digital 3-D takes a movie thrill ride to the next level. I say in 3-D - yes, absolutely, it's worth your time and money. In 2-D - probably not-so-much; that is unless you just like looking at Brendan Fraser and, in that case, it's still only a maybe.