Marvel Cosmic Invasion's next DLC adds a run-based assault on Doctor Doom's castle, giving returning players a different reason to revisit its combat. The Siege of Castle Doom arrives November 10 with the new mode and two playable additions, Doctor Doom and the Invisible Woman. The useful distinction for an owner is that this is a paid expansion built around repeat attempts, not simply another pair of fighters.
Dotemu's gameplay announcement describes routes through the fortress and upgrades that change your combat options. Surviving encounters helps charge Reed Richards' Stabilizer, while collecting batteries and completing challenges supports your progress. You're trying to reach Doom while managing the opposing Siege Gauge.
That setup makes the route part of the decision, rather than just the scenery between fights. If you usually pick a favorite hero and push forward, this is a reason to pay attention to what the next encounter offers. It isn't evidence that a particular route or build will be strongest; that will need to be judged in the released game.
Decide what would bring your group back
In Tribute Games' PlayStation Blog explanation, the perk branches cover offense, defense and tactical options. Reed's Lab also provides unlockable equipment, events and modifiers. The new mode is intended to give you decisions between fights as well as unlocks to pursue across attempts.
For a regular co-op group, discuss which part sounds appealing before treating the expansion as an automatic purchase. Do you want more decisions between battles, or mainly a new character to learn? Would repeating a castle run fit your usual session, or would you rather play a familiar level and stop? Those are preference questions, not things a trailer can answer for you, even when its action looks appealing.
The characters are confirmed in Dotemu's release announcement, but their inclusion isn't a reason to assume every purchasing detail. Before buying, check the add-on listing for your own platform, its final price and what your existing edition includes. If the new mode is the main attraction, wait for released-game impressions of its pacing and difficulty instead of treating the publisher's replayability pitch as a tested result.