Many children around the globe suffer from spider phobia. Virtual reality exposure therapy is an effective phobia treatment, but so far predominantly tailored for adults. A gamified approach utilizing gaze interaction would allow for a more child-friendly and engaging experience, and provide the possibility to foster working mechanisms of exposure therapy. We developed an application in which children make spiders change in positively connoted ways (e.g., make them dance or shrink) if sufficient visual attention towards them is captured via eye tracking. Thereby, motivation for and positive affects during exposure towards spiders are aspired. In this pilot study on 21 children without (n = 11) and with fear of spiders (n = 10), we examined positive and negative affect during exposure to a virtual spider and to different gaze-related transformations of the spider within a quasi-experimental design. Within a one-group design, we additionally examined fear of spiders in spider fearful children before and one week after the intervention. We found that significantly more positive than negative affect was induced by the spiders' transformations in children without and with fear of spiders. Fear of spiders was furthermore significantly reduced in spider-fearful children, showing large effect sizes (d > .80). Findings indicate eligibility for future clinical use and evaluation in children with spider phobia.