The application of code review in a development environment is essential, but this skill is not taught very often in an educational context despite its wide usage. To streamline the teaching process of code review, we propose a browser based "Code Review Serious Game" (CRSG) with high accessibility, progressive level difficulty and an evolvable foundation for prospective improvements or changes. The application is built as a serious game to reinforce the learning experience of its users by immersing them in its story and theme, helping them learn while having fun. The effectiveness of the game components are measured with a case study of 132 students of 2 software engineering courses. The promising result of this case study suggests CRSG can indeed be used effectively to teach code review. The demo video for the game can be accessed at https://youtu.be/FLnr3p4bhOg, and CRSG itself at: https://github.com/barisardic/crsg.