It would be cool for the game to get new achievements alongside with the update. We really, really 100% need them the game really lacks them at the moment.
Sinister Depths:
Welcome to the depths of the Forest Protectors.
A Familiar Guest:
Encounter the Guest.
Escape from the Truth:
You escaped the sinister cult of the Forest Protectors and now revealed the truth.
Welcome to the Den:
Encounter the Guest's hideout.
That's all I can really think of for achievements.