The tutorial tells you about the double jump, but it's easy to miss it, I expected most people to not read it at all haha.
Yeah, the third boss can be brute forced quite a bit with that setup, we realized it after the first one of our friends who finished the game beat it like that. We didn't have that much time to balance it towards the end, so we left it like that, we expected most people wouldn't realize, and if they did, kudos to them. We didn't want to make it too hard for those who didn't use that setup and saw how to cheese it. You can also kill it really fast with dash + triple shot!
And yes, you can jump (or dash if you took that) behind the second boss and attack him a lot. We could have solved it easely by putting the boss closer to the wall so his hitbox would hit you, but decided to leave it like that since that boss can be pretty hard. And it only works really well on every first set of saws, after that, there are usually a couple saws flying around that can hit you when you go behind him, specially in hard mode, where the saws are faster and last longer.
Thanks for playing it to the end, we appreciate the feedback a lot because we hope to improve and expand the game after the Jam.