Designer Toby Fox updated both his personal and the Undertale Twitter accounts yesterday with a series of cryptic tweets: In 24 hours, something was coming. Those who guessed that it was a new game of some sort appear to be right, as the countdown has ended with the launch of Deltarune.

Deltarune is a free download for Mac OS X and Windows PC. It’s a mystery to us what this game is as of now, because Fox neglected to say much. There's some Undertale tie here, obviously; the Delta Rune is a symbol commonly seen in Undertale, most notably on the chest of Toriel, one of its most important characters. And its title, Deltarune, is an anagram of Undertale. But its website bears several warnings in lieu of actual gameplay or story details.

If you're on PC, you may need to override your security settings to install Deltarune. Fox offered instructions on how to do that on Twitter.

I know a lot of people will have trouble with Windows Defender so I made a brief guide to help you. pic.twitter.com/qQStDfcMiI — tobyfox (@tobyfox) October 31, 2018

It’s important to recognize that, according to the Undertale Twitter, this game is far from being done. In fact, the executable is named “Survey Program,” and the application itself appears as “The Beginning.”

“[It] is not complete yet,” reads a pair of tweets in the string from yesterday. “No[,] it is far from complete.” It sounds like player feedback will help Fox build out the rest of the game in some fashion, as the Undertale Twitter encourages fans to offer their reactions to Deltarune.

Undertale first launched in 2015 and hasn't stopped going since, coming to nearly every modern console following its initial PC launch. As one of the many tweets noted, “we have both been waiting such a very long time” for something new from the first-time game designer, who first made his mark composing music for the Homestuck series.

This is a better treat than candy this Halloween, in my opinion. Thanks, Toby; hope this isn't a trick in disguise.