SEGA has today revealed that a free update for Rome II is now available and introduces the festival of Lemuria and an all-new seasonal challenge in Nightmare Mode.

Lemuria was an ancient feast during which restless spirits were exorcised from the home with the alternate offering of beans and then clashing of cooking pots. Perhaps an early Roman version of Trick or Treat?

Nightmare Mode can be toggled on from the game options menu, causing your troops to suffer horrifying visions in battle. Harpies descend from the skies as a terrifying atmosphere envelopes your forces. Assailed by such apparitions it is no surprise that your soldiers will find the enemy extremely frightening!

Any generals skilled enough to complete a Campaign battle in Nightmare Mode will earn a new Steam achievement and the adoration of their peers. May the gods help you if you try to complete a whole campaign.

The latest episode of Rally Point explains more of the update, and we've embedded it for you below.

We've also added a host of new screens from the update you can check out via the thumbnails below.