Theres also the shoggoths. Theyre kind of like a new "infection" that attepts to move to the nearest portal and if it does it brings up the infection rate and summons a Great Old One. They also take three actions do kill and theres only three models. If you cant place a new shoggoth on the board, game over.
Like killerjoe mentioned, you can go insane. But sometimes going insane has its benefits! For example, the occultist character can control the movement of shoggoths with her powers. When shes insane she only has to spend 1 action to move a shoggoth two spaces. Thematically its as if her insanity is fueling her occult powers.
There might be something else I missed, but the shoggoth and insanity mechanics I think are great and make the game feel fresh.