Deltarune Chapter 5 will release in the second half of 2026, developer Toby Fox has said on Undertale's 10-year anniversary.

In mid-June — after a three-year wait between previous chapter releases of Deltarune — Fox promised a faster turnaround on the next episode of the saga, and revealed Chapter 5 was set for a 2026 release.

Now, in a new update to celebrate Undertale's 10th birthday, Fox has admitted that after "factoring [in] the localization and testing," he "doesn't think that the game will be released in the first half of 2026."

"That's not a surprise, right?" Fox wrote. "From last time's updates, you guys have access to exactly how long each step of the development took. Anyway, we don't have any external factors surrounding the release date this time. We'll release it when it's done, and we will continue to update you guys on the progress of its completion. Thanks!"

Fox also took the opportunity to describe exactly where in the development cycle Deltarune Chapter 5 is, revealing that the "early parts" are complete, albeit needing a little polish. The last "40%-or-so" is in a "rough first pass state, and the last 10% is in a prototyping state."

"Probably around 85% of cutscenes have been created up to a first draft state, however, of those at least 20% or so will require more polish," Fox said, adding that regular enemies are mostly done, with at least one programmer already working on the regular enemy bullet patterns of Chapter 6. The "direction of the boss battles" has been decided, and boss attacks have already been planned and completed. The next step is to "arrange the attacks and make adjustments to them if necessary to fit the atmosphere of the battle."

"With Chapter 3 & 4, there were some creative 'hurdles' which made developing parts of the game difficult. How to do the Boards of Chapter 3, how to design the events in Noelle's house, etc.," Fox added. "Once we got past those hurdles and expanded the team, everything went much more smoothly. Chapter 5 was not without hurdles! But... we already passed all of the obvious ones, so there's little to get in our way now! We just need to keep making the game." Only one "main deadline" has been outlined for the rest of 2025, and that's to kick off translation by the end of the year.

The good news is that anyone new to Deltarune still has time to catch up. We thought what we've played thus far is 'Amazing,' awarding it 9/10, writing: "Even though the journey is only halfway to completion, Deltarune's incredible story is already bursting with hilarious charm, unforgettable characters, and an iconic soundtrack that make it worth investing your time in." A "sequel" of sorts to beloved indie RPG Undertale, it has released chapter by chapter starting in 2018, with Chapter 2 releasing in 2021 and the two most recent chapters dropping alongside the launch of the Nintendo Switch 2 earlier this year.

Vikki Blake is a reporter for IGN, as well as a critic, columnist, and consultant with 15+ years experience working with some of the world's biggest gaming sites and publications. She's also a Guardian, Spartan, Silent Hillian, Legend, and perpetually High Chaos. Find her at BlueSky.