A 2D shooting survivor game! Survive in a dark, zombie-infested underground disco and earn money!
When you defeat zombies, they drop money. By using this money in the shop that opens periodically, you can enhance the weapons and characters you own, giving you a greater advantage in battle.
You can upgrade your character based on your score at the end of the game. Even if you can't clear it in a single play, keep challenging it until you succeed.