Background. The heads-up display (HUD) is a useful tool for displaying information to the player in a game, but the HUD is not a part of the game world. This could take away from the desired experience of the game and block important parts of the main action screen. To counteract this the HUD mostly occupies the edges of the screen and avoids drawing the player’s attention away from the main action scene except when it has important information for the player. Only having the HUD visible when it has important information to the player could remove the distraction of the HUD while keeping all the benefits of having one. Objectives. By using eye tracking to complement the HUD, the HUD can be invisible when the player does not use it, and change how the information is presented depending on where the player is looking. By creating a first-person shooter (FPS) game with a HUD complemented by eye tracking, then comparing it to how a normal HUD differed in terms of visibility and clutter, using a survey. Methods. The game was created using the Tobii Unity SDK and modifying the FPS demo scene. To create the gaze sensitive HUD three scripts were created to produce the finished result. Giving the HUD the ability to make all HUD elements invisible and able to appear after passing a specific value or when the element has new information, the HUD also has the ability to present information close to the player’s gaze point in the of notifications. The game was then presented to the participants in the form of two videos one using the normal HUD and one using the gaze sensitive HUD. After watching the partisans answered a survey related to the videos. Results. The gaze-based HUD was generally on par with the normal HUD. The most noticeable significant difference being that the normal HUDs ammunition counter and health bar was proffered over a less visible one. Conclusions. From the results gathered having a gaze-based HUD does not make it harder to notify the player of important information and dos not make the HUD less cluttered, compared to a normal HUD, but there is a difference between them.

First-person shooter (FPS) games are frequently associated with immersion due to their use of a first-person perspective camera, which gives players the impression that they are a part of the game world. When combined with the proteus effect and identification, players can achieve a complete sense of immersion in the character they are portraying. The objective of this study is to delve into the cognitive benefits of engaging in FPS games and to establish a correlation between the level of immersion and cognitive transfer. The data collected from participants who completed reaction tasks were analyzed in conjunction with the IEQ (Immersive experience questionnaire) scores. The IEQ provided quantitative data on immersion. By assessing the participants' cognitive abilities based on their reaction task performance, the study found that playing FPS games can improve accuracy but not affect reaction time. Furthermore, the study found no correlation between immersion and cognitive transfer.