Released back in 2018, Crashphalt is a free and eccentric multiplayer game in which players do ground-pounds to send out seismic ripples, striving to punt each other off-screen. It's got an "overwhelmingly positive" Steam user review reception, as of writing, but that's not entirely a judgement on its quality. You see, Crashphalt is a hit today partly because you need it to run an online multiplayer mod for Toby Fox's wonderful RPG Undertale.

Of Crashphalt's 555 currently existing user reviews, the vast majority were written over five years after release, and either totally disregard or cruelly dunk on Crashphalt. An example: "10/10 Funny Undertale game, will never play this."

It all seems rather hard on Crashphalt's creator, RetroSpecter. It makes me think of cuckoos. I am picturing a sparrow striving to feed a wildly overweight and utterly insatiable Toriel. And yet, RetroSpecter isn't fussed about their game being reduced to an unofficial Undertale co-op patch, commenting that "Undertale came out around the same time I was getting into game dev, and was incredibly inspiring to me." It makes me curious to read about other games that have enjoyed a freak resurgence because they've become necessary for a mod to work.

You can read RetroSpecter's full story on Reddit. "Back in the 2018, I released my first game on Steam for free, Crashphalt," they begin. "It was a little local multiplayer platform fighter in the vein of games like Towerfall and Samurai Gun.

"And while it didn't set the world on fire, it let me learn the ropes of game dev from start to finish, led me to make many friends that I still keep up and work with, and is one of the many stepping stones that led me to working on games full time. These days I don't about Crashphalt too much. But every once and a while I revisit the steam page to see if anyone is still playing."

It was during one of those irregular check-ins that RetroSpecter noticed the user review boom and mysterious glut of Undertale references. A bit of digging led them to Depa's Undertale Together, a local co-op mod that adds new co-op-specific battle mechanics and puzzles. Undertale Together doesn't support online play by itself, but players have figured out a workaround that involves dragging the Crashphalt game files into Undertale, then renaming the Undertale.exe.

The choice of Crashphalt for this purpose appears random. "I dunno why they chose Crashphalt," RetroSpecter comments. "The only requirement for the hack is that the has Remote Play enabled, and I guess it does help that Crashphalt is free. But I imagine there are tons of games that fit that bill. Crashphalt was just the lucky game chosen for the honor."

Again, RetroSpecter is philosophical about all this. "I think its really cool that it's found a way to impact the community even if in a small way and act as a way for friends to play the game together," they write. "So as long as Steam doesn't take any issue with how Crashphalt is being used, have fun playing fighting Sans with your friends."

The dismissive tone of certain Steam reviews notwithstanding, I like to think that a few Undertale players found time to play and enjoy Crashphalt, after mining its guts. As a recovering Towerfall enthusiast, I'm quite taken by the shockwave mechanic. It's like trying to catapult another kid off a bouncy castle.

RetroSpecter is obviously cashing in on the story for self-promotion. There's a cheeky little postscript: "Toby Fox. if you read this, let me know if you... like.. wanna make a game together. Thanks."

Still, no act of relative positivity should go unrewarded on this here internet. So let's end with a plug for RetroSpecter's latest game, Draftula, a blend of roguelike and Tetris in which you cobble together a vampire's fortress from a choice of around 50 rooms with adjacency bonuses.