The progression in this game has been very gratifying. Start out weak, fight off animals that come to eat you, spend the Juice you reap from them to level up and become strong, then become capable of defeating much larger and more dangerous foes - with enough levelling, possibly quite easily.
That being said, it holds interest for only so long before it begins to grow a bit - with pressing, very - repetitive. With enough buffing up, combat- which honestly seems to be the main gameplay element- becomes so easy the risk, challenge, and opportunity for improvement goes away.
Admittedly, best cure for this is to de-level or just start a new game. Another option I'd like to ask for, however, is this:
With the majority of bosses and enemies being the same, my idea I'd like to suggest is the giving a mutation or other variant for common enemies, which causes those enemies' HP, damage, speed, and/or other stats, to rise proportionally to the numerically-represented amount of juice the player has.
This, perhaps, could stack on top of the Monster/Topography level modifier.
This would allow even top-level protagonists a challenge that grows with their own success, which in turn would give us improved reason to keep growing, in addition to our own stats, our weapon sizes/levels, and any other gameplay features which might become increasingly available to us as your vision moves forward.