The 10th anniversary of Undertale has brought with it a wave of speculation and excitement after creator Toby Fox streamed a modified version of the game featuring new content. The stream, held September 20–21, showcased areas and characters never before seen in the original release, leaving fans both thrilled and puzzled.
During the broadcast, viewers noticed the inclusion of expanded areas such as “Old Home” in the Ruins, a redesigned Snowdin Forest, and even an underwater ocean segment with Onionsan. New character appearances also stood out, including a younger version of Noelle from Deltarune and Spamton making an unexpected cameo in Grillby’s. Other additions ranged from humorous touches like Papyrus’ new “Cook Dude” outfit to experimental encounters such as “Verse Sans” and “Battle Sans.” The Wrong Number Song also received a remix, while NPC variety expanded with new hotel residents and a Photo Vent character.
Unsurprisingly, the stream fueled speculation about Gaster, a mysterious figure long central to Undertale fan theories. Observers pointed out deliberate alterations, such as changes to the Gaster Door in Waterfall and moderation efforts that removed Gaster-themed chat art. These adjustments led some players to suggest Fox was teasing future revelations, while others argued that the changes were simply in line with the playful and secretive nature of the event.
Not every fan was convinced the stream hinted at permanent updates. Reddit discussions emphasized that the new areas were part of a custom build created specifically for the anniversary and not content available in any retail version. One user summarized that these additions were “exclusive to a modified version used for the stream,” cautioning against expecting them in future patches. Still, many players expressed hope that select features might eventually find their way into official releases.
The anniversary stream also reminded fans of the series’ ongoing legacy. Alongside Undertale, Fox confirmed that Deltarune Chapter 5 will not launch in the first half of 2026, though progress continues steadily. In the meantime, the anniversary event provided a mix of nostalgia and intrigue, offering fresh content for a game that has continued to inspire discussion and community-driven theories a full decade after its release.
Undertale first launched in 2015, developed almost entirely by Fox himself, and quickly became one of the most acclaimed indie titles of its era. Known for its branching choices, unique combat system, and unconventional humor, the game has sold millions of copies across multiple platforms and remains central to the indie gaming conversation.
