There's a lot to like about this game. For one its a very interesting take on the theme. The graphics are also really well done. But honestly the main thing I dislike is the level design; far too often the player is expected to react to an unexpected spike pit. Odds are that they don't and suffer an unfair death. Which is why I haven't finished the game.
Basically I think you have some excellent ideas, but the execution just isn't there (though frankly that's a really good outcome for your first jam submission).
Also for Game Jams you should always have a web build if possible. Seeing as you made this in Unity, that is an unfortunate oversight (It is extremely easy to compile Unity projects to WebGL)