Castle Wars: Modern is a pixelated retro-style fighting game that offers battle action across modern and futuristic locations using weapons with semi-realistic destructive capabilities. The game features three modes (Battle, Mayhem and Robot Zombies).�
All modes have a 3-minute timer. A player must earn the most points possible to win. They win one point every time they kill their opponent's avatar. They also win one when the character dies and respawns by accident.
A player selects a mode that offers unique landscapes and fighting challenges with or without a friend. In Battle mode, two players (or one creative player playing as both onscreen characters) select a location (City, Moon or Xon). A jet plane intermittently drops new weapons and boxes of medical supplies on the ground. The player can swap their avatar's weapon at any time. They use the medical kit to restore their health meter. In Mayhem mode, the players fight above a fiery lava field.
The third mode in Castle Wars: Modern, Robot Zombies, takes a player or players into a future in which they must fight for their lives against robot zombies that pop out of portals, fly overhead and fire missiles. They can hop around on protective blocks or drop to ground level. That said, the zombies can quickly flank and overtake a player on the ground. This mode also allows the player or players to restore destroyed blocks.