Caught this tonight. No question it started life as a by-the-numbers superhero origin movie. But then it mixes in elements from Masters of the Universe, Flash Gordon (the film it most reminds me of), Raiders, Highlander ... it feels so 80s it needs a Queen soundtrack. The story is more fantasy than science, but it's such goofy fun I quit questioning, say, how people can talk underwater and just went with it. Neither Khal Drogo or Mera ever going to win an Oscar, but the movie serves them well, playing to their natural character. Effects are mostly seamless, just a couple video game cut scenes here or there--the fact they stand out shows how good the rest of the movie is visually, 98% of the movie is effect shots.
Go in ready for a fun time, you won't be disappointed.