Blockchain is a new technological approach that has gained popularity on the market due to its application in several areas such as education, health, security, and smart cities, among others. However, understanding how blockchain works is not easy at first, especially for non-technical people, because it relies on a non-trivial computational process. We have developed a game board - called Blocktrain - whose game mechanics are based on the blockchain processing model. This game gives people the opportunity to learn key blockchain concepts while playing. In this paper, we describe the game design process and assessment of the game as pedagogical instrument.