OK, so this game is short atm but im pretty sure you're gonna lengthen it but a boss idea is The Emperor because i think he would be a good boss.
Human! You are about to become a sword robot! · By
Yes, that is how they will work. :)
You can also use the itch.io app to make the update smoother.
New Idea:
I mentioned platforming before, but why not "borrow" from shadow of the colossus and introduce SpiderTron 50000?
More for novelty given the complexity.
New Idea: (To actually consider)
Ninja Boss Bot. You have limited time to block, after which the boss is stunned/ recoils and you can attempt a strike.