I think this can be a great pack, probably with a mayan style. Here are some ideas and speculations:
- Maybe we'll be able to explore ruins and find out mysteries about ancient civilizations, along with their treasures.
- Dungeons are another possibility. Dungeons could have traps (which you can disarm with the Handiness skill), secret doors, skeleton guards (with the charisma skill you could avoid a fight by talking to the skeleton), other puzzles and of course more treasures.
- New traits and aspirations. I belive an Adventure Lover aspiration is very likely to exist.
- I have different ideas about skeletons. It might be a curse (coming from the skeleton guards previously mentioned). Or what if now you sometimes fail resurecting a ghost? For example, if the ambrosia isn't well cooked the ghost becomes a skeleton as a punishment.
- Collectibles such as snakes, crystals, metals, etc.
- The treasures would be simoleons, collectibles, books, magical artifacts, statues, others. A magical artifact I imagine is a rod of transformation, which lets you transform sims into skeletons or maybe also other life states such as vampires if you have the pack.
We have only seen some seconds of the pack, so it's too soon to say for sure what it will or will not have, but still, we can give ideas.