The ending is an insult to the first movie.
So, okay. Sam and Molly get on the plane, which just happen to be the plane from the first movie. That's fine. But then they see Alex shouting, warning everyone that it's gonna explode. The plane explodes and Alex plus all the others... die.
Yep. You heard that right. ALEX DIES!
Just... what? What the *beep*?