it's hard to evaluate transformational games
edugames don't fit well into the classroom structure and so teachers are loathe to completely revamp their curriculum to support an edugame study. This means that proper studies on edugames are hard to find.
Furthermore, it’s entirely plausible that games have a variety of secondary benefits (such as longitudinal retention) that edugame studies can’t capture as well.
Finally, designing transformational games which is difficult for low budget games researchers to do. (And it’s hard to quantify as an experimental variable. How do you say “oh this game was poorly made” in a paper?)
