There exists a variety of difficulties you can select after beating the game, in the options menu.

I did some quick testing and on the highest setting (Master) everything hits way harder, enemy AI is much more aggressive, and their hp pools are a lot bigger. Conversely on the easiest (Junior) everything is tuned much easier. Maneek for example dies in a single triple special attack.

I think it's clear that the game can be finished much faster on Junior than even on normal and I'm wondering if this should be another category. Obviously there isn't a ton of interest in this game at the moment so it may be a moot point.

Hey, just on the off chance anyone drops by here and happens to know: does dousing the torches in the spirit rooms behind the bosses and then fighting them again do anything? I wasn't able to find anything about it other than how to do it.