*waiting for game to load* *looks away for a sec* *hears intro music* My first thought was. "Yawauht, this is incredibly better that the first already,"
So, I beat bossrush on heroic, got the achievement, "beat" the game again and nothing happened. Not to mention I beat it the boss rush with over half health. So with that said, there is no other ending or anything special about getting all the achievements. ;-;