The concept is a very interesting one indeed, I really like it! I feel like the way the jump height and move speed is affected by the scale gives room for many cool unique mechanics (though I dont have anything specific in mind, I can feel it ykyk)!
some feedbackk: I feel like the dying is a bit abrupt, a little particle or sound effect would definitely give it less of a 'sudden' feeling. Also, the spike collisions are reallly big, making them a bit smaller would make it less stressful and more forgiving for the players!!