This is a really pretty game! I love the pixel art. Gameplay reminds me of rogue-likes where the enemies only move when you do., except with different combat.
The enemy collision could use tweaks - if an enemy is a space away and moves toward your square, it counts as a collision, even if you were moving away from the enemy at the same time -- making the instadeath frustrating. I'd also recommend that items spawn more, even if those items are just regular swords, if the enemy spawn rate stays what it is. Finally, it'd also be nice if enemies didn't feel like they immediately honed in on the player -- making them move a little more randomly, at least when they're far away from the player, would make the horde of enemies more manageable, at least at the beginning of the game.
Like the others have said, there's a ton of potential with this game. Make a few changes to the game to be a little kinder to the player, and you've got a real winner on your hands! Good work.