Xbox PC App Mythic Code Targets Base-Game Achievements, Excludes DLC — Megathread

Xbox PC App 2610.1000.53.0 Ships Mythic Assets Before Any Announcement​

Beebom reported that the update exposed the Mythic symbol and unlock sound, after the Xbox community account Klobrille posted both on X. The German site Xboxdynasty reported the same thing separately: a new update to the Xbox PC app gives further hints about the upcoming Mythic achievement, and its symbol and dedicated sound were discovered for the first time. Microsoft has not announced the feature, explained how it works, or given a date.

This isn't the first sign of Mythic. On September 19, TrueAchievements reported that two new filters, "Completed Mythic Achievement" and "Incomplete Mythic Achievement," had appeared in the Xbox console menus. They sit under the Gaming tab of a user's profile. The filters appeared to be limited to Xbox Insiders, possibly only the Alpha Skip-Ahead and Alpha rings, and they did nothing when applied. Game Rant made the obvious point about the timing: alpha skip-ahead is just the first ring in Microsoft's testing sequence, so it is unclear when exactly Mythic Achievements will be ready for public release.

The public hint came earlier. TrueAchievements and Beebom both say that in August, Xbox CEO Asha Sharma teased a PlayStation Platinum Trophy equivalent for Xbox "later this year." Beebom treated that, together with the new assets, as a sign that launch "should be imminent." The evidence supports something narrower. The client code is in a shipping app, but "later this year" is still a broad aim, not a release date.

Mythic also fits a year of changes to Xbox achievements. In May 2026, Xbox unveiled Gamerscore badges as a way for users to show off how many points they have on their account, awarded starting at 1,000 Gamerscore, according to Game Rant. Around the same time, Windows Central reported that the redesigned achievement visuals were coming to PC. At first, the new achievement system on PC was locked behind the Insider rings.

Mythic Tracks the BaseGame Achievement Group, Not 100% Gamerscore​

Early reports described Mythic as a reward for earning every point in a game. Beebom's summary said outright that players must earn 100% of a game's Gamerscore, although its main text called that uncertain. Xboxdynasty repeated the claim, saying the achievement is expected when a game is 100 percent completed and all available Gamerscore has been earned.

The community preservation site XCT.live pulled apart the retail app package (Microsoft.GamingApp 2610.1000.53.0), including its XboxGameBarWidgets.exe component and resource files, and reached a different conclusion. The app works out Mythic from a set of achievements called a BaseGame group. The unlock notification reads "Mythic achievement unlocked" and says the player "Unlocked all N achievements in the original game." Achievements outside that group are labelled "Add-on." XCT.live's conclusion is that the app counts achievements, not Gamerscore.

This affects real games. As XCT.live notes, the completion percentage Xbox shows today is based on Gamerscore. A game that later added achievements through DLC can show odd results against a player's actual progress. If XCT.live's reading is right, Mythic uses its own fixed list of base-game achievements, so buying or skipping DLC wouldn't affect it.

XCT.live labels what it found directly in the app code separately from what it concluded. These items are in the code:

• The game page gets a BaseGame progress bar that shows "X/Y," and a screen reader announces it as "X of Y original achievements unlocked."
• A "Required for Mythic achievement" filter shows only the achievements that count, and the page reads "All original achievements completed" when you finish.
• Each achievement carries a list of group IDs, and each game carries a completion block that records which achievements in the group are unlocked, whether the group is complete, and when it was completed.
• The app responds only to groups of type BaseGame and logs that it is ignoring any other kind of group-completion notification.
• When a player finishes the group, Xbox Live sends a push notification of type AchievementGroupCompletion, and the app plays the Mythic animation and sound.

XCT.live draws two conclusions from this, and Microsoft has confirmed neither. First, Mythic is a status on the whole game, not a separate achievement with its own Gamerscore. Second, Microsoft decides on its servers which achievements belong in each game's BaseGame group, and it can change that list later. The app only reads the list and does not do the calculation itself.

EnableAchievementGroups Is Off and the Server Sends No Group Data​

Anyone who updates the app hoping to earn a Mythic this week needs to know that two things have to happen first. XCT.live found that everything is gated behind a feature flag called EnableAchievementGroups. A feature flag is a remote switch that lets Microsoft ship code in an app and turn it on later without another release. The app gets its flags from an Xbox service and keeps a copy on disk. That copy held 198 flags, and EnableAchievementGroups was not among them. With no value set, the app treats the flag as off and hides Mythic.

The server isn't ready either. XCT.live says that on September 23, the Xbox achievements API returned empty group-ID fields and no completion blocks. That included new 2026 unlocks in TEKKEN 8, Sonic X Shadow Generations and The Dark Pictures: House of Ashes. XCT.live had first seen the empty group-ID field appear on September 19, the same day the console filters showed up. It calls that the first sign of achievement groups on the server side.

XCT.live's inference is that the code is already in the shipping app, so Mythic could probably appear without another app update. Microsoft would need to turn on the flag and start filling in group data. That makes a server-side launch plausible, where the feature simply appears one day, but it doesn't tell you when.

The analysis also shows where Mythic is not yet. The Mythic code sits in the achievements panel built into the Xbox app, not in the separate Game Bar overlay app (version 7.326). XCT.live says the web builds of xbox.com/play and play.xbox.com had no Mythic or achievement-group code. The Mythic text exists only in US and UK English, and the app's seven other languages lack it. That suggests the feature was added very recently and isn't ready to ship worldwide.

Gears of War: E-Day's Zero-Point Achievement Is a Clue, Not Confirmation​

Beebom argued that Gears of War: E-Day will be the first new game to launch with a Mythic achievement. Game Rant made the same connection. The official achievement list on Microsoft's Xbox Wire does include "The Lucky Ones Died on E-Day," which reads "Earn all other Achievements" and is worth 0 points. The other entries on the list carry point values from 15 to 85.

A zero-point "earn everything" achievement looks like a stand-in for a Platinum. However, Xbox Wire's list never uses the word Mythic. It also doesn't fit XCT.live's code analysis cleanly: by that reading, Mythic is a status the system tracks for the whole game, not an achievement a developer adds to its own list. The E-Day entry may be Microsoft's studio covering the gap until the system goes live, or it may be unrelated. Nothing published so far settles which.

What's certain is the date. Gears of War: E-Day is slated to arrive exclusively on PC and Xbox Series X/S on Tuesday, October 6. Beebom's suggestion that Fable and Clockwork Revolution will follow is a guess, not a report.

Retroactive Mythics and Delisted Games Remain Open Questions​

Achievement hunters with large back catalogs mostly want to know whether games they have already finished will count. XCT.live's reading is "probably yes," but only if Microsoft gives a game a BaseGame group. The server sends each player's completion status and time, so past unlocks could count without any action from the player. The app has nothing that limits Mythic to new games. XCT.live says whether Xbox 360 and Xbox One games get groups is "unknown," because that decision is made on the server.

Several other points are unresolved and affect how much Mythic will be worth:

• Nobody outside Microsoft knows which achievements will go into each game's BaseGame group, and XCT.live's checks of DLC-heavy games like Dead by Daylight, Killer Instinct, HITMAN 2 and Overwatch 2 returned no group data.
• It is not known whether achievements that can no longer be earned, including those in delisted games, will block a Mythic or be removed from the group.
• XCT.live found no reward field in the app, so there is no evidence that Mythic grants Gamerscore, Microsoft Rewards points, or a profile badge.

Beebom's idea that Xbox could reward players for collecting several Mythics is speculation, and nothing in the app supports it so far.

What this means for you​

You can install the update now, but don't expect to earn anything yet. The Xbox PC app updates through the Microsoft Store as usual. Updating gets you the shipped code, but XCT.live's findings show the feature stays hidden until Microsoft turns on the flag and starts sending group data. PC players who want Mythic notifications should know one detail. XCT.live found no separate Mythic toggle, and concludes that the existing Achievements notification switch also controls the Mythic pop-up. If you have achievement notifications turned off in the Xbox app, you probably won't see the Mythic animation either.

• Xbox PC app 2610.1000.53.0 contains the Mythic badge, animation, sound, progress bar and completion-notification code, but the feature is not active for anyone.
• According to XCT.live's code analysis, Mythic counts a game's original achievements and ignores DLC. That conflicts with early reports that described it as a 100% Gamerscore reward.
• Microsoft needs to turn on the EnableAchievementGroups flag and start sending group data from its servers, and XCT.live expects that no further app update will be required.
• Console filters for Mythic were seen only in Xbox Insider builds, reportedly in the Alpha Skip-Ahead and Alpha rings.
• The zero-point "The Lucky Ones Died on E-Day" achievement is a possible clue, but Microsoft has not said Gears of War: E-Day supports Mythic.
• Retroactive support, handling of unobtainable achievements, and any reward beyond the badge and sound are all unconfirmed.

Microsoft has already shipped the PC code for Mythic and seems to be finishing the server side. The October 6 launch of Gears of War: E-Day and Sharma's "later this year" target are the next dates to watch. When BaseGame group data starts appearing in the achievements API, players will find out whether Mythic rewards clearing a game's original achievement list, as the code suggests, and whether older games get it too.

Update: TrueAchievements Reports Retroactive Mythics and Profile Tracking (September 23, 2026)​

TrueAchievements now reports, citing a source familiar with the feature, that Mythic achievements will be retroactive and apply across all Xbox games with achievements. Players who have already completed a title’s base achievement list would receive its Mythic when the system launches, while DLC and title-update achievements would not affect eligibility.

The outlet also says Mythics will be worth zero Gamerscore, resolving one of the unanswered questions in the earlier app-code analysis. It reports that profiles will display a public total of earned Mythics, while completed games will gain a green star, laurel treatment, and border in the Gaming tab.

According to TrueAchievements, Xbox is also preparing a redesigned Gaming-tab header with total Gamerscore, achievement totals, the next Gamerscore milestone, and the Mythic count. Individual game pages reportedly gain a Mythic progress tracker and filtering for only the achievements required to finish the base list; achievements from DLC packs will carry a separate badge.

TrueAchievements says its source expects the rollout soon, though it remains unclear whether Microsoft will begin with Xbox Insiders or release Mythic to all users at once. Microsoft has still not publicly announced the feature.

Update: Additional details (September 23, 2026)​

The dedicated Mythic unlock sound reportedly runs for about 16 seconds—far longer than a standard Xbox achievement notification. IGN highlighted the extended audio alongside the badge and animation assets found in the Xbox PC app, reinforcing that Microsoft has prepared a distinct presentation for the completion award even though the feature remains disabled.