Doctor Doom has a castle, an unstable superweapon and apparently no interest in a quiet evening. Marvel Cosmic Invasion: The Siege of Castle Doom is due November 10, 2026, and Tribute Games has now explained how its new mode turns storming Doomstadt into a series of choices.
The new details arrived in an October 26 developer article by level designer Kevin Chiasson. This is an upcoming expansion, rather than a release happening today. Doctor Doom and Invisible Woman join as playable characters alongside the new Castle Doom mode.
The next door becomes part of the fight
Chiasson describes themed doors offering equipment, rule-changing events, healing, power-ups or batteries for Reed Richards' Stabilizer. Heroes being beaten raises the Siege Gauge, while victories supply batteries to hold back Doom's progress. The castle also introduces hazards, including freezing battlements and dangerous elevator platforms.
Zypher's reading is that the route choices could give a familiar brawler a useful second question. Winning the current encounter is one task. Deciding what the squad needs next is another. A healing opportunity and a chance to strengthen a build do different jobs, especially when the team is already struggling.
Build a squad, not four copies of the same plan
The developer outlines three perk branches: Offense, Defense and Tactical. Perks apply to individual heroes, giving a multiplayer group a reason to coordinate its choices. Stabilizers also lead to Reed's lab, where equipment, events and modifiers can be unlocked. Completing a run unlocks a new color palette for the hero.
That is the part worth watching when the expansion arrives. A large menu of upgrades matters less than whether its choices lead to different decisions during a run. Team specialization sounds promising on paper; this preview is not a claim that Zypher has tested the balance or found a winning combination.
What you need before November 10
Dotemu's current official press kit lists November 10 for the second DLC and identifies Steam, Nintendo Switch, Nintendo Switch 2, PlayStation 4/5 and Xbox among the game's platforms. The Steam DLC listing independently confirms the date and explicitly requires the base Marvel Cosmic Invasion game on Steam. Buying this expansion is not a standalone way into the game.
The press kit currently marks the second DLC's price as to be announced. Check the listing for your own platform before making a purchase; an existing base-game copy or a different expansion should not be treated as proof of ownership of this one. The publisher's gameplay screenshots illustrate the upcoming mode, with the exact capture platform and build unspecified.
Put a Marvel game on your shelf with Zypher
Shop Zypher for a physical Marvel adventure. Check Marvel Ultimate Alliance 2 for PS3 or the Xbox 360 edition. These are separate games, not Cosmic Invasion or its DLC. Match the platform, condition and included items to your setup.
Browse Zypher's game collection, or sell your old games to Zypher when it is time to make space.
Sources and listings checked October 27, 2026. Gameplay screenshots supplied in Dotemu's official press kit for independent editorial coverage: © 2026 MARVEL. Game Software © 2026 Dotemu. Developed by Tribute Games. Images are unmodified, including the original copyright marks; no new Zypher playthrough is claimed.
