Crimson Twilight: Undead Lover is a thrilling simulation game that is available for Android users. The game is developed by Genius Inc and is available for free. The game is set in the town of Crimson Hills, where the player is a monster hunter belonging to the 17th-century Order of Dark Seekers. The player's mission is to protect the town from supernatural minions.

The game features three characters, Sevrin Laurellane, Yusuke Mallory, and Gavin Hallow, who are the player's classmates and also bloodthirsty monsters - a vampire, an oni, and a beastman. The player has to cooperate with these monsters while keeping their secrets to fight against the swarms of undead. The game combines romance, adventure, and mystery, making it an exciting experience for the players.