Spoilers ahead!!!
In the final mission, Atarin never spawned. I don't know if we missed something.
After we broke through the barrier, there was a threat token seemingly representing Atarin on a pile of skulls or something. We interacted with that. The mission objective switched to "Defeat Atarin" but he never spawned on the map. Did we miss something? Or was there some kind of bug? We killed the app before saving in our loss (just before we ran out of time) but we want to find out if it's worth it to play the map again or if we'll lose another 2 hours.
So anybody that fought Atarin in the finale mission can explain how he spawned so I know if we just failed or if I need to contact app support.