With the recent development of Head Mounted Display (HMD) for Virtual Reality (VR) allowing to track and recognize user's Facial Expression (FE)s in real-time, we investigated the impact that the use of FEs as an action-trigger input mechanism (e.g. a FE mapped to a single action) has on our emotional state; as well as their workload and usability compared to the use of a controller button. We developed an Augmented Reality (AR)-based memory card where the users select virtual cards using a wand and flip them using either a FE (smiling; frowning) or a Xbox controller button. The users were separated into three groups: (1) flipping the card with a smile (n = 10); (2) flipping the card with a frown (n = 8) and (3) flipping the cards with the Xbox controller button (n = 11). We did not see any significant differences between our groups in: (i) the positive and negative affect of the participants and (ii) the reported workload and usability, thus highlighting that the FEs could be used inside a HMD in the same way as a controller button.