Pity that description is used as a negative. She's a sweet, likable, well rounded and masterfully acted character who I did not mind stealing the spot light. She certainly puts Chris Pine's Jack Frost's character to complete shame in the "should I care?" factor.
Yep - she was all those things - it's not too much to ask that your main character is crafted with as much care and attention.
<<Why? It worked for Back to the Future and it sure worked for me here.>>>
No. You basically have two kinds of characters in film - those who invoke change and those who are changed by surrounding characters or events, Marty invoked change in all those around him. He taught his father to stand up for himself, taught his mother to be more open, gave Doc (in 1955) something to shoot for and say "what the hell." and read the letter that would save his life - heck, the guy invented Rock and Roll - tell me one person Ralph changed. Not Felix. Not the girl. He's simply there.
This was sold as a boy's movie that quickly changed to an episode of Strawberry Shortcake - there's nothing wrong with Strawberry Shortcake, but I wonder how many people would have seen a movie that was sold with the pitch "Meet Glitch. She lives in a land of candy and wants to be a racer -- there's only one problem, none of the other girls want Glitch in the race because she keeps blinking in and out of the program. Well, she's going to prove that even the sweetest tooth has BITE." This is basically what we got from a trailer that shows a guy wrecking buildings who has an entire arcade to travel through searching for a way he can fit in as a hero.
Oh, and the reason Mario and Donkey Kong were taken out of the movie (they were there at one point) was because they used their basic design for Felix and Ralph - even the game looked like Donkey Kong.