Background: Youths with lower limb dysfunction display low levels of sports participation, which limits their growth and self-development, both physically and mentally. Recently, VR technology has proven its profound value in the psychological evaluation and treatment, rehabilitation, and immersive training of people in need. We have proposed, designed, and developed a VR rock-climbing game for youths with lower-limb dysfunction that allows them to engage in enjoyable and purposeful in-game tasks that simultaneously bring about intensive real-world exercise. Methods: Pilot studies were conducted on college students whose lower limbs were fixed to chairs. Heart rate monitoring, a flow questionnaire, interviews, and observation were conducted for each participant to evaluate the impact of the VR rock-climbing game. The collected data were trimmed on the basis of Cronbach’s alpha and corrected item–total correlation (CITC) to guarantee the data’s reliability. Results: The average value of each flow experience dimension was greater than 4 (0.76 < SD < 0.91). According to the flow-based analysis and the whole-process feeling distribution (WPFD), the evaluated study brought about the participants’ happiness and a sense of mastery and achievement. Conclusions: By bringing about a deep and enjoyable immersion in VR, it remarkably promotes the participants’ intention to participate in exercises.