Let's not forget someone was paid to draw these new sprites, so changing them would be a lack of respect to the one who did it, I don't really think The Echo Project would be pleased to hear someone published another version of the game as it belongs to them, especially with edited files. As Dakyn said, they probably changed it for a reason. I understand you must feel emotionally attached to the all sprites, I am too and I prefer the old ones as well, but things should remain controlled by The Echo Project's decision x)