Undertale is in a period of heavy 10th-anniversary activity, with multiple merchandise lines, concert events, and a museum exhibition planned for 2027. The franchise continues to expand into new collectible formats and live music experiences under creator Toby Fox's supervision.
The 10th anniversary of Undertale has brought a wave of new merchandise and live events. Fangamer reissued four classic T-shirt designs from 2016 and 2017 for the anniversary, and Bandai Spirits launched the Amicotto knitted figure line, supervised by the Japan Amigurumi Association, with seven characters rolling out from July to October 2026. Bandai also opened pre-orders for the Pinch and Connect Mascot 2 gashapon set, which adds a variant of Annoying Dog to the five-character lineup, and re-released the original Pinch and Connect and Tsumande Tsunagete mascot sets in June 2026.
Live music has become a central part of the franchise's expansion. The first official wind symphony concert in Japan, Undertale Wind Symphony in Kyoto, sold out so quickly that a third performance was added for September 22. Nippon Columbia announced the UNDERTALE CONCERT ON 3 PIANOS, a two-format concert touring eight venues starting September 14. A live CD of the 10th Anniversary Concert, recorded across two dates, is available as a made-to-order item, and a Square Enix vinyl release brings two arrangement albums to physical format on September 9.
Beyond merchandise and concerts, Undertale's reach has grown in unexpected ways. A free Steam game, Crashphalt, became an unofficial launcher for the Undertale Together multiplayer mod, and the developer responded positively. The rhythm game Muse Dash released a collaboration song pack with eight tracks from Undertale and Deltarune. The first large-scale exhibition, Undertale Museum, is set for Tokyo and Osaka in 2027, supervised by Toby Fox. The Steam Summer Sale 2026 discounted Undertale by 75% and Deltarune by 20%, the latter a rare move given Fox's stated policy.
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Square Enix released two UNDERTALE arrangement albums on vinyl on September 9 as the fourth collaboration between the game and the publisher. The piano album Echoes Beneath, produced by Yoko Shimomura, arrives as a two-disc black vinyl set with 15 tracks and jacket art by Temmie Chang. The chill album CHITEI DE CHILL carries 20 remixes by ten Japanese artists. Both cost 7,150 yen and are now streaming on Spotify, Apple Music, and YouTube.
The first large-scale UNDERTALE exhibition, UNDERTALE MUSEUM, will run in Tokyo from February 19 to March 10, 2027, and in Osaka from April 22 to May 9, 2027. Toby Fox supervises, with a new key visual by Temmie Chang. Tokyo advance lottery tickets open September 4, 2026.
The UNDERTALE MUSEUM Executive Committee updated the event's official website on September 3, 2026, revealing a key visual drawn specifically for the exhibition by Temmie Chang. The museum is billed as the first large-scale exhibition for Toby Fox's RPG UNDERTALE, and it will run at Ikebukuro Sunshine City Exhibition Hall A in Tokyo from February 19 to March 10, 2027, then at Osaka Nanko ATC Gallery from April 22 to May 9, 2027. Alongside the artwork, the committee released ticket details for the Tokyo venue. Advance admission tickets cost 2,500 yen for adults and 2,000 yen for elementary school students; tickets that include a bonus set of a pin and koban-style amulet are 5,500 yen for adults and 5,000 yen for elementary school students, with preschool children admitted free. An advance lottery for Tokyo tickets opens September 4 at 12:00 and closes September 14 at 11:59, with winners announced starting September 30 at 13:00. The event will partially use a date-and-time reservation system, and entry slots are capped, so tickets may sell out.
Bandai is accepting pre-orders for the UNDERTALE Pinch and Connect Mascot 2 gashapon set starting August 28, 2026, at 11:00 JST through its Gashapon Online service. Each capsule costs 300 yen including tax. The second series includes five characters: Human (referred to as Frisk in coverage), Undyne, Toriel, Mettaton, and Annoying Dog in a variant form. Every character comes in two versions, one with a ball chain and one with a crab clasp, producing ten total types. The mascots measure roughly 3.3 cm, with slight variation by design. As the product name suggests, the figures can be linked together using the crab clasps. Pre-orders remain open until September 23 at 23:59, and Bandai plans to ship orders to homes around late December 2026. The items may also appear at capsule vending machines nationwide before that delivery window, depending on local stock. The copyright line on the product cites Toby Fox from 2015 through 2026.
Nippon Columbia announced on August 5 the performance details, ticket sales schedule, and a new key visual for the "UNDERTALE CONCERT ON 3 PIANOS," a concert featuring music from the game performed on three grand pianos. The event will be held at eight venues nationwide starting September 14, with stops in Aichi, Tokyo, Fukuoka, Kanagawa, Hiroshima, Fukushima, Iwate, and Kyoto. The concert comes in two formats: a Full Program, a suite divided into 11 major parts, and a Short Program, a roughly 45-minute rearrangement without intermission that admits children from age 0. Official advance ticket reservations opened the same day at 6:00 PM and run by lottery until August 11, with general sales starting at 10:00 AM on August 22. The pianists are Masahide Ro, Atsushi Yamanaka, Yusuke Takahashi, Shion Suzuki, and Keigo Takakura, who will take turns on the three instruments. Kazuya Yamamoto, who directed the "UNDERTALE SYMPHONIC CONCERT 2024," handles production and direction, with arrangements by San Shoji. The staging uses lighting effects rather than game footage.
Indie developer RetroSpecter has revealed on Reddit that his free Steam fighting game Crashphalt, released in 2018, is being used by players as a launcher for an unofficial Undertale multiplayer mod. The game, a 2D versus action title supporting up to four players locally, saw its concurrent player count jump from single digits to over 100 in 2022 after a user published a method to enable online co-op for the Undertale Together mod via Steam Remote Play Together. Crashphalt's Steam reviews have since grown to about 550, with 95% positive, earning an Overwhelmingly Positive rating. Many of these reviews mention Undertale, which initially confused RetroSpecter. He investigated and found that his game was chosen because it supports Remote Play Together and is free, though he noted many other games meet those criteria. Rather than being upset, RetroSpecter said he is pleased the game has found new life, especially since Undertale inspired him when he started developing. He also jokingly invited Undertale creator Toby Fox to collaborate on a future project. RetroSpecter is currently working on a roguelite puzzle game called Draftula.
The first large-scale exhibition dedicated to the RPG "Undertale" will be held in Tokyo and Osaka in 2027. The event, called "Undertale Museum," is supervised by creator Toby Fox and will feature immersive, experiential exhibits that let visitors explore the game's world. The Tokyo venue is Sunshine City in Ikebukuro, running from February 19 to March 10, 2027. The Osaka venue is ATC Gallery in Nanko, running from April 22 to May 9, 2027. The announcement was made on July 30, 2026, by the Undertale Museum Executive Committee, with a teaser website and official X account opening the same day. Fox's involvement ensures the exhibition reflects the game's distinctive visual style and themes. The exhibition is described as a space where each step forward fills visitors with determination, a direct reference to the game's mechanics.
The rhythm action game Muse Dash will release a collaboration song pack featuring music from Undertale and Deltarune on July 31, 2026. The pack, titled "Ketsui to Chikara no Uta" (Song of Determination and Power), includes eight tracks total: four from Undertale and four from Deltarune. The Undertale selections are "Death By Glamour," "Last Goodbye," "Battle Against A True Hero," and "MEGALOVANIA." The Deltarune selections are "Attack of the Killer Queen," "It's TV Time!," "BIG SHOT," and "GUARDIAN." The collaboration was first announced on July 22, and the full track list was revealed on July 24 via the official Muse Dash social media account. Muse Dash is available on Nintendo Switch, iOS, Android, and PC via Steam. The game combines side-scrolling action with rhythm gameplay, using a two-button control scheme.
The official Undertale 10th Anniversary Concert account revealed the tracklist and jacket cover for the concert's live CD on July 23. The CD contains audio from the two concert dates held on November 3, 2025, and May 29, 2026, and will include all four programs, A through D. The tracklist features songs such as "Once Upon a Time," "Home," "Fallen Down," "Nyeh Heh Heh!," "Death by Glamour," and "Good Night." The announcement also confirmed that encore tracks from each program, which were well-received during the live performances, will be included on the CD. Orders are being accepted exclusively at the venue and the official concert website, with delivery scheduled for late August. Each CD is priced at 5,800 yen (tax included). The product is a made-to-order item available only through the official website.
Fangamer is reissuing four classic UNDERTALE T-shirt designs as 10th anniversary editions. The shirts, originally released in 2016 and 2017, feature Papyrus, Undyne, Alphys and Catty, and the Amalgamates. Pre-orders are open for two weeks only, with shipping expected in the fourth quarter or later. The re-release coincides with the recent launch of DELTARUNE Chapter 5 and a Steam sale.
Bandai Spirits is releasing a new line of Undertale figures called Amicotto, designed to resemble hand-knitted amigurumi. The series includes seven characters: Flowey, Human, Toriel, Undyne, Alphys, Napstablook, and Mettaton. The figures roll out sequentially from July to October 2026. The Japan Amigurumi Association supervised the design to replicate yarn textures and hand-knitting distortions.
The Undertale Wind Symphony in Kyoto has added a third performance on September 22 after the original two shows sold out immediately. The extra concert will be held at Kyoto Concert Hall, with the same program as the September 23 evening show. The Osaka Shion Wind Orchestra, conducted by Yu Nishimura, performs. A ticket lottery opens July 11.
UNDERTALE is 75% off at 245 yen and DELTARUNE is 20% off at 3,184 yen in the Steam Summer Sale 2026, which runs until July 10. The DELTARUNE discount is notable because creator Toby Fox has said he does not intend to discount the game frequently. The sale follows the June 25 addition of Chapter 5, with Chapter 6 targeting a 2027 release.
Banpresto, a brand of Bandai Spirits, is releasing a new crane game prize figure of Flowey from Undertale as part of its Amikotto series. The figure, supervised by the Japan Amigurumi Association, reproduces the texture of yarn and the unique distortions of hand-knitting to resemble a real amigurumi. It stands about 12 cm tall and will roll out sequentially from July 7, 2026. The series will continue with additional Undertale characters: Human and Toriel are scheduled for August 2026, Undyne and Alphys for September 2026, and Napstablook and Mettaton for October 2026. Undertale is an RPG created by Toby Fox that has received high acclaim internationally, and its sister work Deltarune is currently in development.
Square Enix announced two vinyl records as the fourth Undertale collaboration, releasing September 9. The piano arrangement album features Yoko Shimomura as director and includes 15 tracks like 'MEGALOVANIA'. The chill arrangement album includes remixes by MURO, tofubeats, VaVa, and others. Pre-orders are open now.
SHARE BASE Co., Ltd. announced on June 8 that the first official wind symphony concert for Undertale in Japan, titled Undertale Wind Symphony in Kyoto, will take place on September 23 at Kyoto Concert Hall. Two performances are planned, at 15:00 and 19:00. The concert will be performed by Osaka Shion Wind Orchestra, conducted by Yu Nishimura. Ticket pre-sales begin June 10.
Bandai is re-releasing the Undertale Pinch and Connect Mascot gashapon set in the first week of June 2026. The capsule toy line includes Sans, Papyrus, Napstablook, Temmie, and Annoying Dog, each available in ball chain and crab ring versions for a total of 10 types. The reissue is identical to the May 2025 release.
Bandai is re-releasing the Undertale Tsumande Tsunagete Mascot gashapon figures starting in the first week of June 2026. The set includes five characters-Sans, Papyrus, Napstablook, Temmie, and Annoying Dog-each available in two versions (ball chain and crab ring), for a total of ten figures. Creator Toby Fox supervised the designs.