maybe there's a bug with my version but it won't keep my save file but it's no problem cause i got back to where i was and finished the game in one sitting
also half the time shooting the big spiky crusher boss thing when it's at full health doesn't do anything, maybe you could say it has armor or something but right now it's too inconsistent in both frequency and duration to say "it's a feature not a bug"
the game itself is really good, lovely music, controls not that hard to master, and i also like the concept of using up your health when attacking