Is it possible to do 100% without any guide?

[Ferzh]

Loving the game so far, but I'm curious if at some point will need some guide to finish it all

[lordatog]

You can get the second ending on your own, but going much beyond that isn't intended to be possible alone.

[LonerD]

After 30 hours without any guide I still can't find four eggs and leave the well.
This is the limit of my patience

[Baf]

To be precise: This isn't just a matter of the puzzles being way too hard. There is at least one puzzle where the game gives each player only a fraction of the information necessary to solve it, so that players sharing information is the only possible approach. You'll probably know it when you see it, now that you know that much.