Undertale-like RPG

Long ago, humans and monsters lived in harmony, but eventually that peace gave way to war between the two species. The humans emerged victorious and sealed the surviving monsters underground Mt. Ebott with a powerful spell, where they reside to this day.

Only an enormous force can break the barrier, King Asgore, king of the monsters, theorizes that he will be able to do so with the strength of 7 human souls that he must extract from their bodies.

The ruins: Monster Queen Toriel went into exile here after learning of her husband's plans.

Snowdin: A particularly cold snowy area. A village of monsters adapted to the cold live here, along with the Skeletons Sans and Papyrus.

Waterfall: Very humid caves full of aquatic monsters, Undyne the fish knight is its most prominent inhabitant

Hotland: Very hot, volcanic lands with lava flowing nearby. Scientist Alphys has her laboratory here.

Hotel: Mettaton the artist robot has a hotel at the entrance to the city
Core: The core is a huge complex that generates energy with lava, it was built by the late scientist W.D. Gaster.

Capital: The capital city, where the bulk of the monsters live and the King's castle is, in the latter is the barrier

Monsters are magical beings, many of which are anthropomorphic animals (Undyne is a fish woman, Alphys is a dinosaur woman, Asgore and Toriel are cow men), beings considered monsters (Sans and Papyrus are skeletons), or animated objects (like an airplane with feelings). Their magical form makes them vulnerable to magical things or even human will. They are more flexible but lack determination.

Many people think of humans as a myth. Others resent them, having been imprisoned underground by humans and resenting that life of hardship.

A flower that's the product of an experiment gone wrong. It's quite psychopathic.