There are 2 other endings you can get, and essence helps a lot in getting those. A lot of mana is consumed for the dungeon ending and you also need a fair share of mana for the 3rd ending as well, though not as much.
My main point is it's not really engaging a reward to try and get the essence and go a searching for the other endings when essence gives minimal rewards.
Thus, guess the route puzzle game.
edit: unlike the inspirations, it also does not seem to have the stats effecting how quick events go via skill levels.