Marvel Cosmic Invasion’s Siege of Castle Doom DLC Adds Doctor Doom Mode, Two Heroes

Alex Turner18/08/20264 min read

Dotemu and Tribute Games have confirmed a second paid expansion for their retro-styled brawler Marvel Cosmic Invasion, titled The Siege of Castle Doom. Dotemu’s official press release confirms the DLC will centre on Doctor Doom and add two new playable characters alongside a brand-new game mode, with the expansion set to launch across PC and consoles this Fall.

The announcement, made on August 17, arrives as anticipation builds for Doctor Doom’s live-action debut in Avengers: Doomsday. Beyond a teaser image of the villain, the two studios have kept details deliberately sparse, offering no trailer, screenshots or confirmed character names just yet.

A New Game Mode Built Around Doctor Doom

According to the press release, this upcoming premium DLC will find the infamous Doctor Doom central to an all-new game mode arriving alongside two new playable characters for MARVEL Cosmic Invasion, which the release notes carries a D.I.C.E. Awards nomination. Outlets covering the reveal note that no gameplay footage exists yet, leaving fans to speculate on how the mode will play.

Nintendo Life reports that ol’ Victor Von Doom will be taking centre stage in the expansion, while Game Informer independently confirmed that The Siege of Castle Doom is a paid DLC described as a new game mode that places Doctor Doom front and center, but with no trailer or screenshots, there’s no word on what he’s up to. Some coverage has speculated the mode could echo the survival-style content added to other Dotemu-published brawlers, though the developers haven’t confirmed a format.

Two Unnamed Fighters Join the Roster

TheSixthAxis confirms that the DLC is called Marvel Cosmic Invasion: The Siege of Castle Doom, it will introduce a brand new game mode, and that two playable characters will be added to the roster as part of the DLC. Crucially, the outlet also notes that the likes of Reed Richards, the Human Torch, and Invisible Woman have not been added to the game, leaving them as plausible candidates for the reveal.

Game Informer points out that the last roster additions were pulled from Doctor Doom’s own extended family of foes and allies, noting that the last characters to be added to Marvel Cosmic Invasion were Cyclops and The Thing (who, funny enough, both appear in Avengers: Doomsday) in May. Whether Doom’s next DLC continues down the Fantastic Four and X-Men path or pulls from elsewhere in the cosmic side of the roster remains unconfirmed.

The Second DLC Since May’s Cyclops and Thing Pack

Marvel Cosmic Invasion launched in December 2025 as a co-operative, tag-team beat ’em up from Tribute Games, the studio behind Teenage Mutant Ninja Turtles: Shredder’s Revenge and Scott Pilgrim EX. Its first DLC wave, released in May 2026, added Cyclops and The Thing to the fighting roster and was accompanied at the time by confirmation that a larger Fall expansion was already in the works.

The base game’s story sees the immortal villain Annihilus launch an assault across the galaxy, with Earth’s and the cosmos’s heroes teaming up to fight back using the game’s signature Cosmic Swap tag mechanic. The Siege of Castle Doom marks a tonal shift, moving the action toward Doom’s home turf of Latveria rather than deep space.

Fall 2026 Release Across PC, PlayStation, Xbox and Switch

Dotemu’s press release confirms that MARVEL Cosmic Invasion: The Siege of Castle Doom launches on PC (Steam), Nintendo Switch and Nintendo Switch 2, PlayStation 4 and 5, and Xbox Series X|S in Fall 2026. No specific release date or price has been announced, meaning Australian and New Zealand players will, as with the base game and its first DLC, likely see day-and-date availability once a firm date lands, though local Steam, eShop and PSN pricing in AUD and NZD has yet to be confirmed.

With Avengers: Doomsday arriving in cinemas in December, the timing lines up neatly with Marvel’s broader push to put Doctor Doom in front of as wide an audience as possible before the film’s release. For now, Dotemu and Tribute Games say more information on the mode, the two mystery characters and pricing will follow in the coming months.