yeah right near the begining when you are give the choice to accept the academy's deal or not, if you do not accept it, the game has a couple of scenes and the game ends there.
The game has many choices that impact the relationships and progress of the story. Some choices lead to either a legit "secret ending" or darker paths for a few characters.
We have tweaked almost every choice menu to alert players in advance if something gets super-naughty or goes down a dark path. Sometimes the results are not immediate, so SAVING before marked choices is highly recommended.