Boss level

Boss Levels are levels of a game which are taken up with a major fight against a tough enemy, known as a boss. Bosses can vary in size, shape, and skill, but they must be harder to beat than regular enemies. They should also test the player on a certain skill they have learnt, or otherwise test the player's logic skills and timing.

Say we are making an RPG and one of the main characters has just learned a fire-type spell, and that this was the first fire-type spell in the game. Well, the boss fight should incorporate the fire-type spell in some way, either alone or in combination with other spells and attacks.

Take Bouldergeist from Super Mario Galaxy as an example. The player has just learned how to swing bomb ghosts into objects to destroy them. Thus, this boss forces the player to swing bomb ghosts into the main body of this boss; after a certain number of hits, the boss grows hands as well in order to force the player to be more strategic with their ghost swinging. If you look through both Mario Galaxy games, you will notice that bosses often come after you gain a new ability, and that they test to see whether you have got the hang of them.

So there you have it. It order to make a good boss, it has to test a certain skill of the player in some way. Understanding this should help make your boss battles (and your game) better and more enjoyable.