  Before the computer age, games were played in the physical world where
players would have to interact with real objects and each other, triggering a
series of emotions. Nowadays, the computer games have become one of the most
popular forms of entertainment due to their high-level of attraction and
accessibility. However, the game industry is always trying to find new ways of
making games more interactive and exciting in order to attract new players, and
one of the recent trends on the area of human-computer interaction is
Biofeedback.
  The goal of this dissertation is to study different approaches on the use of
indirect biofeedback within videogames, with the purpose of creating a better
human-computer interaction, and provide a more appealing and immersive user
experience. For this, we focused on the development of a framework capable of
testing different indirect biofeedback models within a specified game, in order
to assess the effect of each of these variations on the user experience. This
framework is game independent, with the intention of being used on further
studies.
