Art: Excellent. Best part of the game.
Sound design: Very simple, does what it needs to do at a basic level.
Player onboarding: It's in a pretty awful state, but you know that. The game needs to give some indication of controls, the eat button, and the pause button. Mechanics can be discoverable but basic controls simply should not be. The main website's control list isn't even up to date.
UI: In the game it's good once you know what's going on. The pause menu with the options and stuff, however, is.... god awful. No sliders for volume and music. Can't have music on when the SFX are off (if you need an easy mute button just make a master slider with a mute button). All the buttons are pictograms rather than words which just causes confusion. A little bit of that can be OK with the most common symbols but making literally everything *only* pictograms is very not ok and there's no reason to do that even on mobile. The game as it stands is also not epilepsy friendly and the button to disable the flashing is, like every other menu object, not marked clearly.
Gameplay: Frustrating. One hit KOs you without a snail shell so death is very sudden. The hunger meter has no mercy and keeps you going at a frenetic pace, woe be upon you if you miss an important jump and fall into a place where you already ate everything. Other than hunger the main killer is falling rocks which are really annoying. As it stands the game is in pure tension between the need to rush to feed the meter and avoiding falling rocks. Those two things killed me far more than anything else in the game. You can try to pick and choose what you eat and evolve into but it turns into a complete hodgepodge anyways because you are often really hungry, there isn't always fruit available. I thought maybe I would get time to look at my future obstacles and plan what to eat to overcome them, but the game is just not built that way.
The mating mechanic is funny, if you have eaten 3 of the same species you can then mate with it, but it is horribly unclear what the crap is accomplished when you take the eggs to a nest. I expected things that would improve my future runs or give me an extra life but instead some particles fly at you and it doesn't seem like anything happens. If you want it to be discoverable it needs to be communicated better than it is now.
In any case the game as it stands is very far from done or being very enjoyable to play. Excellent work on the art though.