Seems like a nice demo. Necromancer was your best fight, old lefty on the other hand a bit dull as all you had to do for the majority of his fight is block. Maybe some power attacks could be added by holding down LMB, counter-attacks if you hit an enemy knight's sword mid flight or something to spice up gameplay, basically give the player more options. Checkpoint system seems okay, not sure if you intended for the player to be able to backtrack and 'farm' health and blood, though. Found no bugs during my run so I wish you good luck on your game.