This is very fun! The movement is clean, the sprites are good, and the combat is also decent. The absolute highlight of the game is the boss fight. It is very well-made. I'm surprised the boss has that many moves! The boot attack is a bit too easy, but the boss fight itself is incredibly fun.
The position of the sword and therefore the attack feels a little weird. Would love to see more variety in enemy types and level design too.
Overall, great job! You made a very fun game all on your own. You should be proud! :)