Context. The feeling of immersion in a video game is something most game developers try to achieve. Immersion makes the player feeling like they are a part of the game they are playing, and causes them to lose track of time and space. Immersion can be achieved in many ways, one of them being through different kinds of Graphical User Interfaces. An integrated interface might help players to get more immersed.

Objectives. The objective of this thesis is to find out whether an integrated or "diegetic" interface improves the feeling of immersion in players.To fullfil this objective, a prototype must be made and then tested using participants who then can answer questions about their level of immersion.

Methods. The prototype was built using Unity, a free game engine. The participants of the study played two different levels with two different interfaces and then answered a number of questions in a questionnaire. The questions were then analysed using the students t-test.

Results. The results of the study showed there were no difference in terms of immersion in the two different interfaces.

Conclusions. These results suggest there is no improvement of immersion when using a diegetic interface, compared to using a non diegetic one.