Together you must go on a long and very dangerous journey, where you will fight with terrible creatures, as well as overcome a bunch of obstacles. Solve the puzzles correctly, this will give you access to further developments. Try to reveal all the most horrible secrets that hide this cruel land. There are several endings here at once, and which one your story will have depends only on the decisions you have made throughout the gameplay.
It mostly resembles a novel. The silent main character constantly walks through endless locations, conducts conversations with the heroes, and from time to time enters into battles. In Undertale, you don't have to kill all enemies - on the contrary, a generous reward is due for the peaceful resolution of any skirmish. And for this there are various methods: from a simple friendly conversation to a complete escape from the battlefield.
And for those gamers who prioritize skirmishes, the developers have prepared a special combat system. Each duel in Undertale takes place in a completely turn-based mode. Moreover, the rules change literally with every battle! Enjoy your pastime!