ABSTRACT
The periodic enemies theme is about enemies that move in predictable, perpetual loops. The periodic enemies theme is, in a sense, the inverse of the moving targets theme. Every periodic enemies theme contains a little of the moving targets theme, and vice versa; that's part of what makes a composite game coherent. Waiting to make a jump or a run is totally normal for the periodic enemies theme, but the sinking ceiling can cause the player to rush and take damage from the fireballs or die in the lava pits. The standard challenge for the level is easy to identify; it consists of single launcher in the middle of the screen. After the standard challenge, the level bounces over from periodic enemies to a kind of non-thematic action section. The theme isolates non-jump movement by use of terrain and the most important property of most periodic enemies.
