Vague spoilers for Deltarune, but I love how fast and loose “optional boss” is.
Chapter 1: You don’t even know he’s there unless you do a bit of side questing. Completely optional, traditional secret boss.
Chapter 2: An optional boss, similar to the above. The twist is that if you take a secret, alternate path, he now takes the role of the main boss at the end of the chapter. Technically optional, because the path is optional, but still pretty neat.
Chapter 3: An optional secret boss in two parts. Part one is the boss hidden away, very missable. Part two is not so much a secret, it’s that it’s an optional challenge to “win”. Finding and beating the very secretive optional boss gives you a great tool against the optional challenge boss.
Chapter 4: The boss isn’t hidden in any way, the only requirement is to find *where* to fight him. Heck, it almost feels required for the story, even if it’s optional.
