Most people tend to hate this film. I think, though, that they hate it because they're looking at it the wrong way. It's one of those movies that has a point, and if you miss that, you don't get any of it.
Their mistake is to watch this expecting a Mario movie. I know, it sounds like the right thing to expect, but hear me out. Fans of the game know what Mario is all about - powerups, angry mushrooms, winged turtles and flying blocks. If you watch this movie expecting that, you'll be disappointed, as you'll find NONE of it. But that's not to say it isn't worth watching.
Picture the scene: a couple of directors are asked to make a Mario movie by Nintendo, and they want it to be live action. That was the flavour at the time - take cartoon characters and make them real. Now, these directors know about Mario. They say "No way can that be done. Mario is all about being a cartoon. Jumping on little angry animals, everyone's a mushroom... It's a great game, and it'd make a good cartoon, but a live action version would just be moronic." "Oh, don't worry about that," says Nintendo, "just so long as you get the main elements in, do it how you want."
The directors go away, rubbing their chins, trying to think of a way to do that but still do justice to the games. And then they have a fascinating idea.
What if they don't do a Mario film, exactly. What if they do a sci-fi film, but fill it to the brim with Mario references, for the keen-eyed game fans?
That's what this movie is. If you watch it with that in mind, you will enjoy it. I've tested this theory out already on a friend who thought the film was a bit stupid when he saw it as a kid, but watched it yesterday with my little thesis in mind and he loved it.