RynoGG

A Deltarune fangame. Kris and Susie suddenly wake up on a flower bed in the world of Undertale. They, along with Noelle, must travel between different worlds to make their way back home.

Team Switched

An unofficial fan-game of Toby Fox's Undertale. Explore a re-imagined world based on the premise of swapping character roles, and adding original content, to create new scenarios.

Goinks

The first UNDERTALE fangame TO BE GOOD.

Sad Bread

Deltarune: Chapter Rewritten created by The Winterer is a roleswap AU with the spirit of a kid's cartoon, follow Asriel, Noelle and Charkis down the dreaded abyss of Kueen's dungeon and free this sad, strange little man.

RickyG

Dontforget Connected is an online multiplayer Undertale/Deltarune fan-game with MMORPG-style gameplay. It features a new underground to explore, over 50 playable characters, new battle mechanics, and much more!

VexSaber

FOUNTAINTALE is a fan-made sequel to UNDERTALE, inspired by elements from it and DELTARUNE as well, adapting both games into a fresh and new experience.

Vision Crew's Deltarune: Alternate Chapters is a fangame project aiming to interpret Toby Fox's earlier concepts and Chapters, it's entirely speculative and plans to be worked on even once his own content is out! It includes familiar characters, even ones Toby has namedropped without a design... or vice versa! But you'll also meet a ton of brand new characters!

Tortas Max

Depper Jar is a turn-based RPG with fast QTE-based battles and different game modes inspired by Mario & Luigi and Undertale.

Deltaruined is a mod of DELTARUNE, the Toby Fox's lastest game to the date. This mod includes both chapter 1 and 2. Enjoy Completely new battles! New Cutscenes! (original cutscenes reworked too!), new mechanics and a lot of unused content restored!

You pushed the limits of this world one too many times. And now you must deal with the consequences of your actions.

You play as Spamton, who has fallen in a Neo Dark Fountain inside Kris's pocket, and now explores a strange, dreamy place called the Cluttersphere. With your perspective shifted, having Jevil as your ally (?) and being tasked with protecting Kris's lifeforce in the form of a candlelight, you must use the SOUL to guide Spamton into making it back to the Dark World safely.

One day, the trio found themselves caught between getting caught from the teachers around the corner, or risking everything and jumping into the strange grey door. Leaving their school and world behind. After a long fall Scuta wakes alone, with only one option to go, he has to proceed further, finding his friends and leaving the new dark world.