Toby Fox Comments on Deltarune Development Progress

Deltarune Chapter 5 is still several months away, as a new message from Toby Fox sets a realistic timetable for the release of the next installment in the episodic bullet hell RPG. While fans still have a long time to wait, progress on Deltarune Chapter 5 is coming along nicely, and its creator wants fan to know what to expect as it creeps nearer to completion.

The follow-up to the wildly successful Undertale set in an entirely different universe, Deltarune‘s first chapter was released exclusively on PC on Halloween 2018, with ports to PlayStation 4 and Nintendo Switch following just a few months later. Fans who dove in at launch had to wait almost three full years for the second chapter to release in September 2021, with Deltarune Chapter 3 + 4’s release date taking even longer, launching across all platforms in June 2025, just in time for the release of the Nintendo Switch 2. With three more chapters planned, the next installment should leave fans with a lot less downtime, but exactly how much is still not a certainty.

What to Expect From Deltarune Chapter 5

Deltarune’s new chapters have set the stage for what comes next, and while the adventure can sometimes be unpredictable, foreshadowing is abundant.

Deltarune Chapter 5’s Progress is ‘Going Excellently’

The last big update on Deltarune Chapter 5’s release date was revealed by Fox around the middle of September, projecting that fans will be able to dive into it sometime during the first half of 2026. Now, an even newer update from the creator, posted in the game’s official winter 2025 newsletter, seems to indicate that previously revealed timetable will still hold true, if not making it seem a little optimistic. According to the newly revealed information, Chapter 5 will require “several months to release the game from where we are now.” That leaves a large, vague window of time for a potential release to fall under, but Fox has detailed a lot of things that have to happen before the next chapter is ready to make its debut.

Deltarune How to Raise the Bridge in Chapter 2 (Acid Tunnel Puzzle)

A progress report shows that a lot of work has gone into the current project already, stating that all the rooms in the next chapter have been completed except for some needed work in touching up the backgrounds. Likewise, all the game’s scenes are practically finished, needing just a slight bit of polish to get them ready for release. There are just a couple of battles that remain unfinished, but they are all already technically functional from beginning to end, with a few boss battles in Deltarune Chapter 5 needing some adjustments to their bullet hell patterns and pacing before Fox can officially declare them as complete.

Looking towards the future, the update states that localization of Chapter 5 is already underway, and once that phase is completed, it will be ready to move on to a professional testing phase. Additionally, in January, it will be time to shift focus to making sure the game runs properly on all available consoles. Considering that the first four chapters of Deltarune on Nintendo Switch 2 make use of its mouse mode, and that this feature may return as part of Chapter 5, this part of the process could potentially throw some challenges at Fox as he works to ensure that all versions of the game are as bug-free as possible at launch.

There’s no exact estimate on the particular length of Chapter 5, but Fox promises that it “contains hours of fun!” The length of chapters in Deltarune has increased since its early days in 2018, with full completion of Chapter 4 taking roughly double the time it takes to pull off the same feat in Chapter 1. Chapters 2 and 3 fall neatly in the middle of that constantly rising gameplay length graph, so some fans may be expecting Chapter 5 to deliver an adventure that will take completionists more than 10 hours to play through.