Kids love playing games so I developed this lesson to let them create and make a science game. This includes an introductory letter, student instructions and checklist, a feedback sheet for students to use when they play the games and a self assessment sheet. I use this as part of the unit on the cardiovascular and respiratory system but you could modify it for any body system or systems or other topics in science as well. Creating a game that is playable and covers the material thoroughly requires a great deal of critical thinking, planning and cooperative work. My former students all tell me this was their favorite and most memorable activity.