A very cute game!
I didn't have issues surviving the first day, the warning that it was getting late helped and the star indicator of where your shelter is, though I don't know why that tree is really any different from any other tree. Also, I get that you want more variety in barriers than just rocks & logs, but the grass & clover didn't feel dense enough to block movement, maybe the models should be thicker.
I liked the progression, getting dashes, then the yarn hookshot, then the materials for a bag, etc. Not sure what the swimming trunks actually did, since it's not like the mouse knows how to swim anyway.
The darkness is really brutal, I got lost getting back to my shelter one day and by like 9 PM it was too dark to see anything on my screen. Your other indicators give you much more time from when they start alerting you to when you're dead.