Dotemu and developer Tribute Games released the second DLC for Marvel Cosmic Invasion, titled Marvel Cosmic Invasion: Siege of Doom Castle, on November 10, alongside update 1.10/2.007. This patch is a mandatory download for all players, even those who have not purchased the DLC.
The DLC adds the Doom Castle mode, featuring a repeatable in-run progression structure. Players must breach the defenses of Doctor Doom's stronghold, advancing through branching paths, new enemies, and time-limited challenges, while selecting from 12 traits to enhance defense, damage, or tactical capabilities. Mission failure may inflict debuffs on characters.
Players can also obtain permanent equipment, events, and rule modifications affecting subsequent challenges from Reed's Lab. Two new playable characters are the Invisible Woman, who can bend light and manipulate force fields, and Doctor Doom, who utilizes high-tech armor, mystic abilities, and his genius intellect. All playable heroes have received new color schemes, and original composer Tee Lopes has created new dynamic music that changes with gameplay.
Marvel Cosmic Invasion: Siege of Doom Castle is now available on Steam, Nintendo Switch, Switch 2, PlayStation 4, PlayStation 5, and Xbox Series X|S for $7.99, with a 10% launch discount until November 17. The bundle including the base game and two DLCs released this year is priced at $37.99. No additional gameplay balance adjustments were found in this update.