I used a nifty software package called FPS Creator (short for first person shooter) a little while ago to build a 3D game as a learning resource. (You may have read about it previously here, here and uh here).
It works essentially as a glorified multichoice quiz, giving the learner a choice of three doors to go through representing the answers to a question. There is a "pain zone" behind two of the doors which reduces the player's health, makes an unpleasant noise and flashes red when they pass over it. Behind the door with the right answer, any lost health is restored and my charmingly reassuring and encouraging voice tells them - "That's right, well done".
I finally used this game in a workshop on using video today and it was really interesting to see how learners responded.
I had a group of five women, aged between their twenties and fifties, none familiar with playing 3D games.
While there are instructions at the beginning explaining that users can use the W,A,S and D keys to move around and the mouse to look around, nobody realised that you need to (or can) use both simultaneously. As someone who has played 3D games for the odd hour or ten thousand, navigating an environment in this way seems self evident and so it was very useful to see this from the perspective of a newby.
A couple of them even said that moving through the space made them feel slightly sick - probably not the best outcome for learning but again something to take into consideration.
A learner who had the sound turned off didn't realise that the "pain zone" with the redness and decreasing health score (which is not necessarily something that you would notice) was a bad thing.
Watching the users with the game confirmed a few concerns that I have had with the design - notably the fact that you only get to read/hear the question once. If you forget the question or the answers, you don't really know where to go. This might be resolved by having the question and answers appear physically in the 3D space (on the walls and doors?).
While I thought that the direction players/learners have to move was clear (always up the stairs), it became obvious that when players became disoriented (unfamiliar with navigating 3D space), they could go backward, down to areas that they had already been. Signage on the walls (arrows) might help in this regard.
It may well be that the use of this kind of environment for learning might be better suited to people more accustomed to 3D games or it might be useful to include an introductory level in a simple open space that introduces new players more effectively to the control system.
All agreed that it looked impressive at least but I don't think there was a lot of enthusiasm for this approach in general. (Which isn't to say that it isn't worthwhile, just in need of tweaking.)