One of the most beloved indie games of the last decade, Undertale still inspires fans to create unique reimaginings and expansions of the original game by Toby Fox. Fans will recognize most games on this list, but one didn't make the cut: Overtale.

Unfortunately, development on this game stalled out, but the rest of the games on this list are playable now, some right from your browser. Explore new tales about Sans, Toriel, Frisk, Chara, and all the other monsters from Undertale. Bonus: there is even a fan game with PvP and multiplayer!

Updated on September 26, 2021, by Juliet Childers: Though some fan games remain in purgatory, many others continue to spring up to the glee of fans of the original game. The characters keep evolving as fans craft unique takes on their perspectives or create entirely new characters for players to talk with and battle. And, of course, there are plenty of Sans battle simulators to frustrate even the most zen of gamers.

15 Memory

This fangame features 3 routes for players, 7 endings, and 3 unique final bosses. It's also one of the only fangames that acknowledges the original Undertale story in a very meta way. Created by LUKELCS, the game even includes an original character in Bucky the bunny.

It sticks out as one of the newest Undertale fangames as it was published in only September of 2020. But perhaps the best feature of this fangame is the expanded and original dialogue paired with plenty of puzzles to keep players busy.

14 Underfell

images from VLG Games Underfell

There are many different iterations of Underfell, but this one comes from VLG Games.

This is the Undertale fan game to play if fans love unforgiving experiences like Dark Souls. The game takes place in an AU with extremely powerful and aggressive monsters. Furthermore, one wrong move on top of a trap can spell an instant game over for the player.

Fights in the game also represent significant endurance challenges as opposed to tactically different battles.

13 Undertale Red

image of character Red in battle from Undertale Red

Many fan games for Undertale feature just one epic battle with different mechanics or unique characters. For instance, Undertale Red pits the player against a character resembling a Little Red Riding Hood-themed monster sometime after befriending Undyne in the timeline.

Her attacks can cut the bullet board into a number of different pieces to complicate things. "Red" also expresses her desire to be in Undertale with some distinct lore of her own.

12 Horrortale

images of Sans from Undertale fan game Horrortale

In the fangame Horrortale, Undyne has now become Queen after a long time of neutral rule by Frisk. Her laws cause a famine, driving the monsters mad from starvation and her own torture. Monsters now eat humans rather than harvest their souls.

The player embodies another human named Aliza who is weak and shy but has a penchant for cruelty. Though you cannot take the genocide route, the player must navigate this dark new Underground and survive. The fancomic by Sour Apple Studios inspired the game. The game, in turn, inspired fan art, too.

11 Overtime

image of Sans next to the Medic from Undertale fan game Overtime

Though there are now many games like it such as Overwatch, Team Fortress 2 pioneered what would become MOBA-type first-person shooters. With such a strong fanbase itself and iconic characters like the Medic (now Sani on the right with Sans on the left), the game makes a natural fit for a crossover with Undertale.

In Overtime, Miss Pauling travels across the Badlands to kill the Mann Brothers. Will she fight the mercenaries trying to kill her or not? The classic genocide/pacifist question still remains.

10 Don't Forget

images from Undertale fan game Don't Forget

The original Undertale is a single-player experience, but Don't Forget offers players more options. There is PvE (described as pretty grindy), but also PvP and multiplayer. With an official release last month, the game is still very much alive.

Players take on the part of Harlow who lives with the Dreemurrs (adoptive family) on the surface. Monsters and humans co-exist, but something isn't quite right. Don't Forget also employs some mechanics from Deltarune which has the first chapter available for free right now. This fangame shows off just how much story-driven games can impact gamers.

9 Disbelief

image of Flamesatgames user's game Disbelief Papyrus

While still only about 20% completed, many fans in the Undertalk community cannot wait for Disbelief to finish mainly for its unique depiction of Papyrus. YouTuber Flamesatgames is behind the game that has Papyrus judge the player since this AU has the player take down Sans instead.

Papyrus is very powerful, but the way he tries to reason his way into fighting the player has been described as "heartbreaking." It adds another dimension to the Papyrus character and fans can't wait for the completed game to launch.

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

image of player fighting Sans in Bad Time Simulator

Undertale will turn five in September, so celebrate by having a bad time. Enter: Bad Time Simulator and Yet Another Bad Time Simulator by Joe Zeng. You can play Sans in 3D like this YouTuber does or play Endless Sans in any internet browser right now. The reimagined boss fight going from 2D to 3D offers a new experience for fans of the original title.

Like other classic titles including Castlevania: Symphony of the Night, Undertale features excellent music that makes every encounter unique. In BTS and YABTS, the original soundtrack appears, as well, so you can create new bad memories of the epic Sans boss fight with great music.

7 Undercards

image of Undyne and Annoying Dog from Undercards

If fans don't want a multiplayer experience, but still want an Undertale-inspired game with different mechanics, look no further than Undercards.

Available on their website and even on the Google Play Store, Undercards employs characters, items, and more from the original game. This is also one of the most supported and popular fangames by far with support for community chat and friends lists. There is even a ranked mode with monthly seasons and rewards.

6 INK Sans

image of two AU Sans fighting the player for Undertale fan game INK Sans

Described by some as the ultimate Sans battle, this one-fight-only fan game has the player trying to go for a genocide run whilst being thwarted by not one, but many different Sans characters.

Each Sans that joins the fight adds new challenges for the player from lasers to cleavers to bones and more. The only gripe some fans have about it is that there is only one song for the fight. Be warned: it is for gamers who want an extreme challenge.

5 Understory

images of characters in Undertale fan game Understory

Some fans have described Undertale as one of the hardest games ever. Others who might skip games like Dark Souls will favor this fangame that focuses more on lore with a little twist on the fighting mechanic from the original game. Like Horrortale and Don't Forget, Understory features a human player character in a setting post a True Pacifist Undertale run. The story also features a human other than Frisk or Chara. However, humans and monsters are still at war with each other.

As a young boy named Nick, the player falls into the Underground to find that monsters have lost faith in all humans. To quote Fred the Gladiolus, "In this world, it's kill or be killed."

4 Dusttale

image of Sans and Papyrus from Dusttale

A favorite amongst fan games, Dusttale imagines a dark future for the monsters where Chara has initiated an endless genocide run. The player cannot control the human's actions and must watch as Chara slaughters all in her path. But the story isn't so bleak: Sans remembers it all. And he wants to stop the cycle.

The inversion of the lore with the faithful level of remaking also includes a reimagining of the classic soundtrack for even more atmosphere.

3 Undertale Green

image of the Three Brothers battle from Undertale Green

In this prequel fangame, the human soul of Kindness named Cody falls into the Underground much like Frisk does. He must aid Undyne in figuring out why this mysterious virus is spreading throughout the monsters. With five chapters in total, chapter three of Undertale Green released in April of this year.

But in a big difference from the original game, monsters bleed upon genocide. The developers have said that this has plot relevance in future chapters. Fans can check out some of the boss fights here.

2 Unfair Undyne

image of Undyne from Undertale fan game Unfair Undyne

Joe Zeng didn't stop with BTS and YABTS when it comes to Undertale fangames. The commitment to crazy boss battles and intentional bad times continues in Unfair Undyne or NGAHHH! Simulator. Though she might have become Queen this time, Undyne still calls the shots here.

Available from your browser, this fun rhythm game offers a challenge players can take on whenever and wherever. Be aware that, as other gamers have noted, it can get frustrating. After all, the player only has four health regardless of the game level. With the original Undertale having made the jump to switch awhile ago, gamers can keep their fingers crossed for these titles which should be joining Undertale soon.

1 Dylantale

image for Dylantale an Undertale fan game

Though development on this fangame is not ongoing, it remains one of the most notable and favorite among fans. Dylantale takes a page from the "slice of life" genre in that the player controls Dylan: a yellow blob who desperately needs to get an A+ to get his mom off his back. It still includes "Pacifist" and "Genocide" runs, but instead of monsters and humans, the world has "Failures" and "Not Failures."

With many traits that make it unique, Dylanetale reminds people why indie games can explode into cult classics overnight. See all the blobby goodness and test anxiety in YouTuber LiNX 4's video.