Thank you! The objective is shown on the menu screen, and the exit and the Big Face are spawned in a random location each time. Sorry you didn't make it through the exit, it's a flat plane in 3D space. Maybe in a future update I'll make that exit plane always face the player, like the enemy model does, so you don't miss it by walking the wrong way.
Edit: This is also my first Unity game, so it's sort of expected to be really clunky. The gameplay was made in like 3 days, and I mostly spent time on optimizing things to decrease lag from the godrays, heh.