Love the game, found all potions, but couldn't find the sword. But I'm sure you already have an idea how to fix that.
I found a bug right at the start of the game, where I went left, climbed up the wall and died to the barrier. But i was still able to move around even though my character was invisible and I managed to jump off the map by keep walking to the left side and pressing space. My character never respawned and the game over screen never showed up, so i had to restart the game. I played it in the web browser.
Maybe change the block that the candle's stand on. It looks the same as the block that you can jump on / collide with and I kept jumping on those blocks and wondering why i fall through, until i noticed that they all have a candle on top of them. Maybe make them similar to the background, so that it's clear, that you can't jump on them.
Other than that, great game, good introduction, love the visuals, the music and the sounds.