[Hakulyte]

You have automatic saves every time you get a new sigil, you can go there and then load a previous save before it happens. I actually did something dumb about that, I picked the axe and went to every place with wood walls and then I went to the door only to realize that I had to do everything again because nothing in these gave me sigils. /oops

So, if you unlocked stuff or get stars, make sure you go grab an extra sigil to save. Otherwise, go for it. Eternal Life \o\

You can do everything with one game in terms of endings if you're careful about it. Achievements may take some redo for certain flags that trigger events @ Milton by example.

I hope these doesn't count too much as spoilers as it's not information directed at how to solve puzzles.