>>712550001>kinda, but you can also just use the savestate to practice the boss, then run the stage from start again when you feel like you have a good grasp at the boss.I know that feeling.
Cave Story's final boss isn't that hard and is a fun fight, but you have to Run Hell every single time to even attempt him, so if you get into a new phase, get destroyed and then want to practice it, you've gott'a Run Hell again, and again.
Last time I played, I mostly fumbled my way through the whole game, but the memories of Running Hell and fighting Ballos were so engrained I did it perfectly first attempt without any issues. It was quite nice, actually.