This area is something I haven't thought of as much as the appropriateness, so please do feel free to add to and dispute anything I say here! J
There are of course lots and lots of ethical issues to consider when making an emotive adaptive game. For instance, people may object to have their emotional states and/or changes monitored to begin with, and many may not like the idea of the game storing this information for future use (in TEDDI the information was stored for future use only for a minute, but as I had to do analysis afterwards all data was written to a log file). The information storage could be short and temporary (e.g. 60 seconds long buffer), or it could be more long term allowing the game to learn more about the player, thus aiding in adapting the game in meaningful ways. Many people are wary of any information being stored about them, and though it is not obvious to me how this sort of information would be misused, it is an important issue to consider. The way I see it however, is that if people were worried about their data being stored and misused they would likely not choose to play the game, and so this issue is avoided. Designers should be aware of this issue though when determining their target group.
To keep the post fairly short I'll only mention one other ethical issue at this time, namely the issue of adapting a computer game when played in a player vs. player mode. In a battle between two players, the game can't adapt the players' skill levels or luck, as this would make the game unfair to the better player. These sorts of adaptations are exactly the sorts used in TEDDI, which was a one player game only. So what can be done about this versus situation? I would suggest that the environment to be adapted, the colours of the scenery (even subtle changes could have an impact), the tone and speed of the music, and other environmental aspects specific to the game. This could aid in making a player feel better or worse about the situation, without actually helping or obstructing the game play in favour of one player and without interfering with the battle.
What do you guys think of these ethical issues, and possible solutions? And more importantly, what sort of ethical issues do you envisage with emotionally adaptive computer games?