We encourage all volunteers to leave feedback after they complete a project. However, it’s not mandatory and they might prefer not to. In our experience, lack of feedback generally means that the person is doing a good job and delivering work that their peers find of appropriate quality 
Please, don’t get discouraged and keep delivering good-quality tasks - we are sure that peer reviews will arrive!
This page gives you some more context on how you check if you have received reviews on your tasks, and see your overall score.
We’d like to stress that access to volunteer tasks is not restricted in any way by the number of reviews and the score you might receive.