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: This is where the Monster Queen Toriel exiled herself after learning of her husband's plans.

Snowdin: Snowy area, particularly cold. A village with 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 inhabitants

Hotland: Very hot, volcanic land with flowing lava nearby. This is where scientist Alphys has her laboratory.

Hotel: Mettaton the artist robot has a hotel at the entrance of 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 being 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 a plane with feelings). Their magical form makes them vulnerable to magical things or even human will. They are more flexible but lack determination.

Many think of humans as a myth. Others are resentful because they were imprisoned by humans underground and resent that life full of deprivation.

A flower that is the product of an experiment gone wrong. It's quite a psychopath.