Is the goal of the game obvious? How descriptive of a tutorial is needed?
I don't think the goal of the game as a whole is readily obvious. I think it would be nice to have some kind of comic or splash screen upon starting the game that guides the player to look for plants would be nice. Also to have keybindings either on the screen during play or in that splash screen would be nice too. Finally, I would recommend having some kind of sign or direction to the shop would be nice because it took me a minutes to find it after initially walking past it.
How's the minigame? Is it rewarding/punishing enough?
The minigame was great I was able to start consistently get three or four samples per plant after a minute or two of playing. I believe it is fine as is.
Glaring issues with the village?
Some signs would be nice for a bit of direction, the art style and layout are nice and don't need any tweaking in my option.
Does the music fit the world? Any suggestions for music? (it plays a song from a playlist at random every 5 minutes)
I didn't hear any music in the few dozen minutes I was playing, that or it was extremely quiet.
Anything Else?
The minigame seemed to have an occasional bug where the mouse would disappear, I didn't notice any pattern to this happening but it happened to me twice.
It is fairly easy to clip into objects like the village houses and the rocks in the village by moving into them diagonally at the right angle.
Finally the shop keeper design is very cute I really liked them.