Keep the oncoming enemies from reaching the castle wall. Land mines will help hold them off. Some enemies take several hits, do not be thrown off guard by them. Accuracy is important, the more enemies you hit in a row the more points you will receive for each kill. Hitting enemies will also fill up your power gauge. When it's full you can unleash a devastating attack. You can also save up several volleys to release at a later time. Volleys can be exceptionally helpful, do not be afraid to use them. Also a second player can play as a bomber. The bomber is controlled by the mouse, and clicking will launch a bomb. The bomb will hit where ever the circle is at the time of launch, so time your launches carefully. There are two modes of play, Level mode and Marathon mode. In Level mode, you advance to more challenging stages of play. Also, depending on your difficulty and number of players, you will acquire magic which be activated in the magic vault, and will aid you in the game. In Marathon mode, the difficulty increases in real time. You cannot acquire magic in Marathon mode.