Undercards

A free-to-play Undertale-themed card game. Also features Deltarune and Undertale Yellow cards!

Undertale: Kindred Spirits

PurrSum

Undertale: Kindred Spirits is an Undertale fangame that tells the story of Batty and Mel, who possess the purple and blue souls respectively! Hiding from the Underground's Royal Guard, their journey takes many twists and turns, ultimately challenging their partnership along with whether the food is actually good - down here in the underground.

Undertale Red & Yellow

Shinix

Have you played Undertale Yellow? After completing it, did you think: "Man, I really wanna replay Undertale now, but I've already played it so many times..." No? WELL TOO BAD! Introducing: Undertale Red & Yellow! An Undertale mod designed to scratch that Undertale Yellow itch!

Vision Crew's Deltarune: Alternate Chapters

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!

Deltafall

Team Nexus

Deltafall is a Deltarune AU where the original trio discovers that their school was built after a science facility that conducts dangerous experiments with the dark world. In 1977. A top secret corporation has found a way to harness the power of dark worlds to create any worlds they wanted. IDEATION INC has one goal. To create the perfect world. For all lifeforms. Not bound by reality. But bound by imagination.

Deltamon

Team Paradox

Explore the vast region that Kris calls home as you aid them in becoming champion! Your rivals Susie, Noelle and Berdly join alongside you to see and catch over 200+ pokémon from Kanto to Paldea!

Deltarune: Hypothesis

uprank

A Deltarune fangame featuring a collection of hypothetical scenarios, each imagined as a fully playable segment of gameplay. Discover the hidden mysteries that connect these scenarios as you dive into each one, unraveling an existential truth about you and every adventure you’ve been on so far.

Undertale: Call of the Void - Placek's Take

Placek

Undertale: Call of the Void [Placek's Take] is an alternate interpretation of Undertale: Call of the Void, originally created by Saster and J-Bug. Developed by Placek and the COTW Team, this version introduces multiple unique endings, enhanced graphics, and fresh twists while preserving the signature Call of the Void style.

Undertale Green: The Pre-Show

Experience a one-shot adventure setting up the vibrant characters of Undertale Green through a drab snippet of the surface! Interact with an unorthodox battle system, make new friends, and prepare for the long road ahead.

Team Delusional's Dusttale

Team Delusional's Dusttale is our own take on the well-known AU: Dusttale, which in itself is a fangame of Toby Fox's Undertale. You will face many new roadblocks as the entirety of the underground questions your motives, and a familiar hooded figure looms over your every move. Will you choose the easy way out this time, or will you strive for a better tomorrow?

Undertale Plus

The Undertale Plus Development Team

Undertale Plus is a mod that allows you to have your own completely customized Undertale experience! Bringing all-console exclusive content of the original, with widescreen support, colored sprites, custom battle backgrounds, bug fixes, and many more with add-ons.

Underswap: Echoed

Breakfast Bunch

“Underswap: Echoed” is the Breakfast Bunch’s reimagining of the popular Undertale AU, Underswap.

Desktoptale

Toastworth

Desktoptale is a tiny program that puts a fully controllable Undertale, Undertale Yellow or Deltarune character of your choice on your Windows desktop!

Dusttale Reimagined

Team Reimagined

Ever wanted an Undertale fangame that completely re-builds (or rather, REIMAGINES) the concept of Dusttale from the ground up? Well you're in luck! This game is just for you! Explore the Underground, meet old friends in new situations and join us in this race for DETERMINATION against Flowey your best friend in Dusttale Reimagined!

Undertale Together: Next Soul

Depa31, AngelaPuzzle

A mod of Undertale where you can play with two characters!

Depper Jar

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

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!

Sonic 3 & Tenna

techncolour

Eggman's off on vacation, Ring Racing, so Tenna came out of Eggman's TV and took everything while he was gone. Blast through Sonic 3 with a Deltarune twist! With over 18 completely new bosses to fight, 6 new gameplay gimmicks to endure, and a modified story, Sonic 3 & Tenna completely transforms the game into a new, yet familiar experience! Not a Undertale, Deltarune or UTDR fan-content fan? That's okay! The bosses have been designed with Sonic gameplay philosophy in mind, and the entire experience itself is stand-out enough to not require any prior UTDR knowledge.

Underswap: The Reckoning

Epickthan

Out of all the possible paths you can possibly entwine yourself into, this one in particular will prove to really challenge your palette.

Deltarune: The Upper Hand

Sad Bread, The Winterer

Dive into the capitalist utopia of New Yolk and engage in the short story of Sockswald. Building up to the climactic fist-clenching bossfight against HANDROMEDA.

NightFell

Team Starlight

Trapped in a forgotten world atop an enchanted mountain, Monsters have been confined to an endless darkness. Life on the CROWN is dangerous and hopeless, with many monsters turning to cruelty to stay sane. On Halloween night, Jackie accidentally stumbles into this terrifying realm. They're told the only way out is at the highest peak of the mountain. With that in mind, Jackie sets out to climb to the top with their best Friend, Flowey. Will they forge friendships with the battle-worn residents that call this Hell a home? Or will they succumb to the ruthless law of this land... "Kill or Be Killed?"

Dusttrust X

Awesome Games

From the developers behind the fangame Green Snas, Dusttrust X is a revitalization of the original Dusttrust AU as well as a spiritual successor to Legacy Underswap: Thanatos. You play as both Chara and Sans as you explore a broken version of the world you once knew and see how they both react to the new situation they put themselves in of their own doing.

Undercreator

Sil