This study aimed to determine the effectiveness of a bilateral, self-supported, upper-limb rehabilitation intervention using a movement-based game controller for people with chronic stroke. Fourteen participants received a control treatment, followed by a washout period, and then the intervention. The intervention comprised playing computer games with the CyWee Z (CyWee Group Ltd; Taipei, Taiwan), a movement-based game controller similar to the Nintendo Wii remote. The CyWee Z was incorporated into a handlebar, making bilateral exercises possible by allowing the unaffected side to support and assist the affected side. The intervention lasted for 8 to 10 sessions of 45 to 60 minutes over a period of 2.5 weeks. The Fugl-Meyer Assessment upper-limb section (FMA-UL) was used as the primary outcome. The Wolf Motor Function Test and the Disabilities of Arm, Shoulder, and Hand outcome measure were used as secondary outcomes. Postintervention, motor performance as measured by the FMA-UL was significantly improved compared with all preintervention assessments (p < 0.001), whereas no changes were found on both secondary outcomes. It can be concluded from this pilot study that upper-limb motor performance of adults with chronic stroke improves with repetitive, game-assisted, self-supported bilateral exercises.