What a unique concept, at first sight i thought it was just a platformer with a single sprite but i was delightfully wrong. The mechanic of adding and substracting parts and them interacting with your total mass for different jump heights is filled with possibilities and requiring a specific shape for the end makes level design managable.
My only grope with this game would be aesthetics, get some cool style and oh god please throw that chromatic aberration shader to the river and have a viking funeral for it.
Theme, the only one sprite is cliche and detrimental but being "one with the world" is what really sells the adherence to the theme.
Originality, in spades, a great original concept in a sea of 2D platformers, a breath of fresh air.