Free Steam Game Crashphalt Becomes Unofficial Undertale Online Launcher
The incident shows how an unintended use of Steam Remote Play Together can turn a buried free game into a community support tool, and the developer's tolerant response highlights a rare case where a mod's popularity benefits the original work.
Key Facts
- Crashphalt is a free 2D versus fighting game released on Steam in 2018, supporting up to four-player local multiplayer.
- The game's concurrent player count rose from single digits to over 100 in 2022 after a user published a method to enable online co-op for the Undertale Together mod via Steam Remote Play Together.
- Crashphalt has about 550 Steam user reviews, 95% of which are positive, earning an Overwhelmingly Positive rating.
- RetroSpecter is currently developing Draftula, a roguelite block-dropping puzzle game that won first place in the Fun category at the GMTK Game Jam.
- Undertale Together is an unofficial mod that adds up to four-player local co-op to Undertale, released in 2019.
Reporting from 2 sources: Automaton, Game Spark.
Indie developer RetroSpecter has revealed on Reddit that his free Steam fighting game Crashphalt, released in 2018, is being used by players as a launcher for an unofficial Undertale multiplayer mod. The game, a 2D versus action title supporting up to four players locally, saw its concurrent player count jump from single digits to over 100 in 2022 after a user published a method to enable online co-op for the Undertale Together mod via Steam Remote Play Together. Crashphalt's Steam reviews have since grown to about 550, with 95% positive, earning an Overwhelmingly Positive rating. Many of these reviews mention Undertale, which initially confused RetroSpecter. He investigated and found that his game was chosen because it supports Remote Play Together and is free, though he noted many other games meet those criteria. Rather than being upset, RetroSpecter said he is pleased the game has found new life, especially since Undertale inspired him when he started developing. He also jokingly invited Undertale creator Toby Fox to collaborate on a future project. RetroSpecter is currently working on a roguelite puzzle game called Draftula.
- Crashphalt is RetroSpecter's first Steam release, and he credits it as a stepping stone to becoming a full-time developer.
- The game's combat uses shockwaves from falling attacks rather than direct punches or kicks; the stage floor ripples based on charge time, and the goal is to blast opponents off the stage.
- Undertale Together, the unofficial mod that adds up to 4-player local co-op to Undertale, appeared in 2019 but had no effect on Crashphalt until 2022, when a user published the Remote Play Together workaround.
- RetroSpecter said the only requirement for the method is Remote Play Together support, and he speculated his game was simply the "lucky" one chosen among many free options.
- He posted on Reddit partly to answer a review asking how a developer feels when players only use the game to mod another title. His reply: "I don't mind at all. I've already moved on to other projects, so I think it's really great that this game has been given new life."
- He added that Undertale came out around the time he started developing and strongly inspired him, and that influencing the community as a trigger for playing with friends is "very cool."
- His playful postscript to Undertale creator Toby Fox: "If you're reading this, please let me know if you want to make a game together. Thank you."
- RetroSpecter's current project, Draftula, is a roguelite block-dropping puzzle game where players stack room blocks to build a castle and manage synergies between rooms. It took 1st place in the "Fun" category at the GMTK Game Jam on itch.io.
- Some of the new Crashphalt reviews are hostile, including one calling it "a work suitable for not playing," alongside the many Undertale-related ones.
Synthesized by Yomimono from the 2 cited sources below, including Japanese-language reporting where cited, then editorially reviewed before publishing.