MARVEL Cosmic Invasion - The Siege of Castle Doom expands the core side-scrolling beat 'em up experience with two new playable characters and an additional game mode. The base title combines classic arcade-style combat with a tag-team system that lets players switch between paired heroes on the fly. This expansion centers Doctor Doom as both a fighter and the focal point of its new content, set within his own fortress.
Gameplay
Combat revolves around the Cosmic Swap mechanic. Players select two heroes per run and switch between them instantly to chain combos, call assists, or adapt to enemy patterns. Each character carries distinct movesets, including specials and ultimates on cooldowns, alongside basic attacks, dodges, and blocks. The system encourages pairing complementary styles, such as melee-focused fighters with ranged or aerial options, to handle groups of foes or bosses effectively.
Up to four players can join in drop-in co-op, either locally or online, with difficulty scaling to match the group size. Progression involves leveling individual heroes through repeated play, unlocking passive upgrades and visual options via a central hub. Stages feature side-scrolling layouts filled with waves of enemies drawn from Marvel lore, including allies of the main antagonist Annihilus. Hazards, environmental interactions, and boss encounters add variety without altering the fundamental brawler loop.
Game Modes
Campaign Mode forms the primary single-player or co-op path. It guides players through a sequence of stages across multiple locations, complete with story beats, optional challenges per level, and character unlocks. Progress saves allow continued runs, while each stage rewards experimentation with different hero pairs.
Classic Arcade Mode strips away narrative elements for a high-score focused run. It limits lives and continues in the style of traditional arcade cabinets, pushing players toward mastery of combos and survival under pressure. Unlockable modifiers further customize these sessions once earned through campaign play.
The Siege of Castle Doom expansion introduces a dedicated new mode built around Doctor Doom and set inside Castle Doomstadt. This addition expands the roster with Doctor Doom, who wields self-designed tech armor, occult abilities, and strategic intellect, alongside Susan Storm as The Invisible Woman, whose cosmic-ray powers enable light-bending and force-field manipulation. Details on the mode's exact structure remain limited ahead of its November 10 launch, but it places Doom at the center of events in his headquarters.
Characters and Roster Expansion
The base roster features fifteen Marvel heroes at launch, with earlier DLC content adding Cyclops and The Thing. The new expansion brings the total higher by including The Invisible Woman and Doctor Doom. Each addition carries unique abilities tailored to the tag-team format, allowing fresh team compositions that mix established favorites with these arrivals. Heroes level individually, gaining strength and options that carry across modes.
Is It Worth Playing?
The base game has drawn positive reception for its faithful recreation of retro beat 'em up pacing blended with modern co-op accessibility and the inventive Cosmic Swap system. More than 1.5 million players have engaged with it since the December 2025 release. The expansion adds meaningful variety through new fighters and a Doom-focused mode, appealing directly to fans of the genre who enjoy roster experimentation and Marvel crossovers.
Players who favor short, replayable sessions or deeper co-op coordination will find strong value in the core loop and upcoming content. Those seeking extensive single-player depth or narrative complexity may find the experience lighter, as the focus stays on action and score chasing. Availability on PC supports straightforward access for those interested in the full package once the expansion arrives.
