This study examined whether socially shared regulation of learning (SSRL) enhances students' algorithmic thinking performance, promotes learning participation and improves students' learning attitudes through game-based collaborative learning. The students learned algorithmic knowledge and completed programing tasks using Kodu, a new visual programing language made specifically for creating games. The teaching and learning program lasted for six weeks, during which time the students attended a 45-minute algorithmic thinking class every week. Students in the experimental group were engaged in SSRL, whereas students in the control group were not. All the students completed three algorithmic thinking tests and a learning attitudes questionnaire. The results revealed that the students in both groups gained knowledge during the game-based collaborative learning and that there was not a significant difference between the two groups with respect to learning performance. However, SSRL had significant effects on student learning participation and learning attitudes. The results suggested that game-based collaborative learning environments enhanced students' algorithmic thinking performance. In addition, SSRL, when incorporated in game-based collaborative learning environments, promoted student participation in learning and improved students' attitudes towards learning. This study provides important insights into game-based collaborative learning with SSRL intervention for instructional design.