In this paper, we report a case study using two easy-to-deploy psychophysiological measures - electrodermal activity (EDA) and heart rate (HR) - and correlating them with a gameplay experience questionnaire (GEQ) in an attempt to establish this mixed-methods approach for rapid application in a commercial game development context. Results indicate that there is a statistically significant correlation (p < 0.01) between measures of psychophysiological arousal (HR, EDA) and self-reported UX in games (GEQ), with some variation between the EDA and HR measures. Results are consistent across three major commercial First-Person Shooter (FPS) games.