As in the title: the screenshots reminded me of Stardew Valley - which I liked, although I modded some things I didn't quite get along with.
Is the gameplay of Kynseed going to be similiar, and will modding be possible?
Stardew valley doesn't exactly SUPPORT modding. I had to look through the code of some mods and things would be much easier if it did. It's just some clever people noticed it's written in c# which can be easily decompiled, analyzed and its API called, hooked and patched on the fly.
BTW I think both games are written in same c# framework, there might be KMAPI in some unspecified time in the future even if game itself doesn't support mods.