Hidden blade automatic knife games Do you like weapons, especially knives? Then this discharge knife simulator is for you. An excellent collection of 3d automatic knives is waiting for you in your device. There are 16 types of flip knife available in the game. Popular butterfly knife, karambit and other cool knife hit. All knives are interactive. Real sounds of opening. Made real animation and controller. For example, select the butterfly knife and shake the device. The knife hit will open. If