Undertale Together is a mod which allows the game to be played in couch co-op, but players have several ways of using the mod to play online co-op.
Undertale is the hit retro-inspired RPG which released in 2015 and was solo developed by Toby Fox. The game sees players controlling a child trapped in the monster populated Underground and attempting to make their way back to the surface world. Undertale was sold on its innovative encounter mechanic which left it up to the player whether they would attack enemies or play as a pacifist.
Undertale tells an extremely compelling story full of interesting characters and plenty of jokes, and although the game is designed as a single player experience, many players wanted a way of bringing along a co-op partner similar to the retro games that Undertale took so much inspiration from.
In 2019 a modder named Depa31 released a mod for the game named Undertale Together, which allowed two players to control two separate characters through the game’s story and encounters. The mod not only allowed for two players to experience the game, but it also introduced a competitive aspect as one player could attempt to kill enemies while the other could try for a pacifist run of the game, and although this is not the way players should ideally experience Undertale's story for the first time, it did offer a lot of replay value for veteran players. The mod only allowed for local couch co-op, however.
This meant that players who wanted to play the game online with friends were at a loss because the Undertale Together mod requires both players to use a shared keyboard with one player using the WASD keys and another using the arrow keys. Fans have since shared methods of using this mod online by sharing a virtual desktop. PC Gamer recently described a method of using a remote desktop tool named Parsec in order to virtually connect the player's keyboards and play Undertale with an online friend.
A Youtuber named DrownedInGames has also released a video which showcases various apps and tools that a player can use to get Undertale Together playable with an online friend, along instructions on how to use each program. Online co-op for Undertale is a unique way to experience the beloved indie title and would be most beneficial to fans of the game that have already played through the game solo and are familiar with the various endings in Undertale that players can aim for.
In October 2018 Toby Fox released the first chapter of a follow-up game named Deltarune. The game shares a lot of narrative similarities to Undertale but the game's combat system as been completely overhauled. Fans of Deltarune were quick to give the game its own co-op mod similar to Undertale Together.
Undertale is available for PC, PS4, PS5, PS Vita, Switch, Xbox One and Xbox Series X/S.
Source: PC Gamer