Inclusion Criteria:  Male or female, 18-80 years old; Unilateral ischemic or hemorrhagic stroke at least 6 months and no more than 5 years prior to study enrollment; Upper extremity hemiparesis as characterized by initial scores on upper limb subtest of the Fugl-Meyer Assessment (FMA-UE) between 12 and 40; Some active pro-supination range of motion; Some active metacarpal-phalangeal joint in the hemiparetic hand; Intact cognitive function to understand the robotic therapy procedures (MMSE>23 and able to follow 3 step command) during initial evaluation visit;  Exclusion Criteria:  Undergoing upper-limb rehabilitation therapy during the period of the study. Severe spasticity (defined as a Modified Ashworth scale score of 3 or more) that would prevent safe use of the robotic system; Visual impairments as assessed by the NIH Stroke Scale Visual Field subscale (only subjects with no visual loss will participate in the study); or hemispatial neglect that would impair the subject's ability to play the interactive games (as assessed with the line bisection test); Severe proprioceptive deficits that impair the ability to process haptic or visual feedback, as assessed by physical examination during screening; Communication impairments such aphasia that impair the subject's ability of providing feedback (as reported by a physician in his/her medical record); Individuals with open wounds or recent fracture (<3 months) in the upper extremity, fragile skin or active infection; Upper-extremity orthopedic injuries or severe pain resulting in movement limitations.