The document describes a game concept called "30 Souls" where the player must defeat 30 monsters across 30 stages within a limited number of lives. They have 30 "Souls" or lives total - if they take damage from a monster, they lose a Soul and the stage restarts. If they run out of Souls, the game ends. Each monster has a visible weakness that must be hit to defeat it. The game has both a normal and challenge mode, with challenge mode giving less time to defeat each monster.