The primary objective of this pilot randomized controlled trial (RCT) is to test the feasibility (recruitment rate, retention rate, participant burden, adherence, technical issues, safety) and usability (system usability scale, SUS) of Omnidirectional treadmill Virtual Reality training (omni-VR) among chronic stroke survivors. Our secondary objective is to (1) estimate the extent to which cognition, brain activation during a dual task activity, walking ability, and dynamic balance change after 3 months of training among intervention participants (omni-VR) and traditional exercise controls, and (2) estimate the extent to which health-related quality of life and motivation co-evolve with our secondary outcomes. Researchers will compare the intervention group and control group to evaluate the impact of omni-VR on cognition and physical function among stroke survivors. Participants will: * undergo a 45-minute training session 3 times per week for 12 weeks * intervention group: omni-VR * control group: traditional exercise program (strengthening and walking activities)