9 Best Undertale Fan Games That You Should Know Update 05/2024

Best Undertale Fan Games

Undertale, which was made by Toby Fox, is one of the most popular independent games of the last 10 years. It still inspires fans to make new versions and additions to the original game. Fans will know most of the games on this list, but Overtale didn’t make it.

The development of this game stopped, but you can play all the other games on this list right now, some of them right in your browser. Find out more about Sans, Toriel, Frisk, Chara, and all the other Undertale monsters in new stories. Plus, there is a fan game that has PvP and multiple players.



This fangame has 3 ways to play, 7 endings, and 3 different bosses at the end. It’s also one of the few fangames that makes a very meta reference to the original Undertale story. The game was made by LUKELCS, and Bucky the bunny is an original character.

It stands out because it is one of the newest Undertale fangames. It came out in September 2020. But perhaps the best thing about this fangame is that it has a lot of puzzles and new and expanded dialogue.


Underfell has been made in many different ways, but this one is from VLG Games.

This is the Undertale fan game to play if you like games like Dark Souls that are hard to beat. The game takes place in an AU where monsters are very strong and mean. Also, if the player makes a mistake on top of a trap, the game is over right away.

Instead of just being different in terms of strategy, battles in the game also require a lot of stamina.

Undertale Red

Undertale Red

Many Undertale fan games only have one epic battle with different rules or characters. For example, in Undertale Red, the player faces a character that looks like a monster from Little Red Riding Hood after becoming friends with Undyne.

Her attacks can break the bulletin board into many pieces, making things harder. “Red” also talks about how she wants to be in Undertale with her own story.


After a long time of neutral rule by Frisk, Undyne is now Queen in the fangame Horrortale. Her rules cause a famine, which makes the monsters crazy from hunger and her own pain. Now, monsters eat people instead of taking their souls.

The player takes on the role of a weak and shy person named Aliza who likes to hurt other people. Even though you can’t choose to kill everyone, the player still has to find their way through this dark new Underground and stay alive. The game was based on the fan comic by Sour Apple Studios. Fan art was also made because of the game.



Team Fortress 2 was the first MOBA-style first-person shooter game. There are now many games like it, such as Overwatch. With such a big fan base and well-known characters like the Medic (now called Sani on the right and Sans on the left), the game is a natural fit for an Undertale crossover.

In Overtime, Miss Pauling goes across the Badlands to kill the Mann Brothers. Will she fight or not fight the mercenaries who want to kill her? The old question about genocide and pacifism is still there.

Don’t Forget

The first Undertale game is for one player, but Don’t Forget gives players more choices. There is PvE, which has been called “pretty grindy,” as well as PvP and multiplayer. Since it came out last month, the game is still going strong.

On the surface, players take on the role of Harlow, who lives with her adoptive family, the Dreemurrs. People and monsters live together, but something isn’t right. Some of the game mechanics in Don’t Forget come from Deltarune, whose first chapter can be played for free right now. This fangame shows how much games with stories can affect players.



Even though Disbelief is only about 20% done, many fans in the Undertalk community can’t wait for it to be done, especially because of the unique way it shows Papyrus. Flamesatgames made the game where Papyrus judges the player, but in this alternate universe, the player fights Sans instead.

Papyrus is very strong, but people have said that the way he tries to talk the player into fighting him is “heartbreaking.” It gives Papyrus a new side, and fans can’t wait for the game to be done so they can play it.

BTS And YABTS (A.K.A Endless Sans)

In September, Undertale will be five years old, so have a bad time to celebrate. Enter Joe Zeng’s Bad Time Simulator and Another Bad Time Simulator. You can play Sans in 3D or Endless Sans in any web browser right now, like this YouTuber does. Fans of the first game will have a new experience with the boss fight, which has been changed from 2D to 3D.

Like Castlevania: Symphony of the Night and other classic games, Undertale has great music that makes each encounter feel different. The original music is also in BTS and YABTS, so you can use it to bring back bad memories of the epic boss fight with Sans.

Pokétale by GammaRay

Pokétale by GammaRay

When you mix Pokémon and Undertale, what do you get? Well, of course, Pokétale.

Pokétale is (sort of) an Undertale-style retelling of the first Pokémon game, Gen 1.

This fan game is great for people who like both Pokémon and Undertale because it combines their stories, art styles, and fights.

You already know that we at RetroDoo like Pokémon, so we had to include this one.

This is a short and cute game to get you ready for some of the awesome fan games on the rest of this list.

If you like Pokémon, we also have a cool list of the best Pokémon fan games for you.

Yet Another Bad Time Simulator DELUXE by Seezee

Did you ever wish you could fight a boss in Undertale in full 3D? Well, dude, you can!

It’s like if Undertale took place in the world of Doom.

Check out our list of the best Doom games if you like the game.

ZweiHander was the first person to work on YABTS, but his project file was lost forever.

So Seezee made the deluxe version to keep the project from going away and being forgotten.

Another short and easy experience, but one that you should definitely back. Even more so when you know how long the project has been going on and how much love has gone into keeping it going.

We’re happy to put it on our list of the best fan games based on Undertale.