Queen Debra and her Demon army, having vanquished the Ghouls, are now a formidable threat to the Demonic realm. The Skeleton Army of the Undead is in need of a capable leader to defend against this new danger.

Undead vs. Demon is a marble shooting game developed by FunTriggerGames. The game follows the story of your undead army as they face off against Queen Debra and her legion of demons. Defeating the Demon army requires strategic leadership from the player. The game features pleasant 2D visuals and the ability to customize your Demons. The music is calming and the sound effects are thrilling. Players can change the direction of their undead army by tapping and holding the screen. Once the adjustments are made, the Skeleton King must be commanded to lead the Undead army into battle.

In battle, if the undead army hits a demon, it will sustain damage, and if it hits a wall, it will bounce back. Each level includes a boss fight where players must survive multiple waves of demons. Upon defeating the boss and completing the level, players are rewarded with gold, jewels, and gear. The Skeleton King’s stats can be improved by equipping gear; two items of the same level can be merged to create a higher level item. The quality of the gear ranges from white (lowest) to red (highest). Normal gear can be upgraded with gold coins, while advanced gear can be upgraded with jewels. Precious metals like gold and diamonds can also be used to summon powerful undead soldiers. The strength of these soldiers is randomized, but players can combine two soldiers of the same level to create a stronger one.