User blog comment:N7EagleEye/New Mass Effect 4 Details/@comment-68.36.22.19-20130709034023/@comment-11582483-20130710203521

The problem with that is that the ending would be predictable and linear. Mass effect is based on your decisions in the game and the end is decided therefrom (even the third game wasn't such a good example) which results in a very dynamic story line. The aforementioned is the whole appeal of the game. So, having any kind of prequel would, i think, waste the appeal of the game because the ending would have no change.