As you might know, I have a separate project called Superhero Movies (.net). It shows all the released and upcoming super/action hero related movies, including links to the character's profiles. I'm currently working on integrating the movies into the SHDb website.
There's already an option to rate the movies. Not just a general score, but you can also rate a movie on different categories, like; directing, story, acting, etc.
The movie part of SHDb will play a bigger role of the website and will show the general info, user ratings and you'll be able to write reviews.