I recall I got stuck twice during the playthrough, for a day or more each time. Not going to say exactly on what, so as to avoid spoiling, but in retrospective, these things, while not obvious, were definitely something that can be deduced (and in the end I did figure them both out without resorting to hints).
It felt something like “OK, I absolutely know that I need to get this item, or to do something with this thing here”. So even if nothing is obvious, I’m going to try everything in this room/area, until I find something that works. Oh, was that it? Yeah, I guess I could have thought about that earlier, haha.”