I was wondering about this, since Novedicus posted this text in one of his posts about the Dr. Yundong hack. Well, I thought that every game had the same engine. So, what's the differences about them? and why it was necessary to make them, and why they didn't stick with the S1 engine for the rest of the games? Also, is this also applicable with sound drivers? This one, I surely know why, but I don't know how.