Delirium is a sudden, fluctuating disturbance in consciousness and cognition and is highly prevalent in older surgical patients. Delirium is preventable; non-pharmacological interventions, such as cognitive stimulation (CS), are the best preventive strategies. Implementing CS in acute hospital settings is a significant challenge due to limited resources and low patient engagement. Virtual reality (VR) and gamification for CS delivery could be a scalable, engaging solution. Based on my preliminary work, I hypothesize that VR- based CS games will be safe, feasible, and acceptable in high-risk older patients (Aim 1). The proposed study will estimate the intervention's effect on cognitive functions, particularly sustained attention (Aim 2), and the incidence of postoperative delirium (Aim 3). To accomplish the above goals, I will conduct a randomized controlled pilot trial involving 90 patients ≥65 years old with pre-existing cognitive impairment admitted to the hospital following a major surgery. Patients will be randomized 1:1:1 to receive VR-based CS games (intervention), watch a VR movie (VR control), or receive standard-of-care nurse-led reality orientation (Nurse control). The trial will provide me with preliminary data to support an R01 application.