Even though it's titled Kick-Ass the real star of the film is Hit Girl. Once you're introduced to her character you eagerly await her next scene. Hit Girl's action sequences are on par with the best and Chloe Mortez is definitely taking her career to a new level post 500 Days of Summer.
If you haven't seen Kick-Ass yet watch it before it leaves theaters. And then buy it on DVD/Blu-ray. It's that good!