I used gamification in my classrooms previously in that I gave students points for doing the things I wanted them to do, such as using the class website. They could then use these points for rewards, and thee was an extra reward for the student who had the most points. The results were that the students who would do those things anyway got all the points, and those who didn’t just gave up because they were always behind. Similar examples are making games out of worksheets and giving points or prizes for those who finish first or whatnot. The kids aren’t fooled; they know these aren’t really games and you’re trying to trick them into doing the work.
That’s why in school it’s important to make a distinction and focus on game-based learning, instead. Use games that require the skill you are trying to get them to practice, but in order to accomplish something else, so that doing the work isn’t the goal of the activity.