Bioshock, it's (not really) just like Disney's the Little Mermaid!

Let's examine the similarities.

A magical adventure under the sea, with singing and dancing, villains and heroes. The protagonist is born under the sea to a ruler, who then spends time on land before returning to the sea. There are women concocting potions and magical-like effects that sometimes transform people. A strone theme is the desire to live on both land and under the sea. And the desire to go onto land, where the people are. And a cast of whimsical and sometimes racist charicatures under the sea.

The list of similarities goes on and on.

There's even a big ol' crab. And a big underwater castle/fortress. And girls having magical adventures in the company of watchful males who are supposed to be watching over them. And a villain who tries to use borth manipulation and force to try to take over the kingdom of the protagonist's father, but is ultimately defeated by the protagonist, etc.

See what further similarities/parallels you can come up with!