Seeing as it is a game with lots of animals in it and a focus on exploration, I was wondering whether it was appropriate for my 7 year old (with translating done by me). But a complete lack of age rating makes that hard to decide.

I'll answer my own question here: Steam shows a PEGI 7 rating for "Lost Ember".

I wonder why GOG does not show this rating. I buy games for my children, and I prefer DRM free games, but not showing an age rating clearly will make me rethink buying.