Hi there! I really enjoyed playing your game.
I did find a pretty game-breaking bug, though: If you get a coin stuck between you and your sword, the coin counter just goes up infinitely. Mister knight here is causing some massive economic damage lol
I have no clue whether this was intentional or not, but since enemies can't go through coins, you can build yourself an impenetrable wall of wealth (which was very fun).
I will have to dock some points for the limitation, though. You wrote that "The final boss is unbeatable", but by the end of my coin-hoarding it couldn't even move. I think that's a draw :D
Anyway, good on you for learning Godot! I hope you had fun and keep joining jams in the future! You clearly have potential and I'd like to see more.