The music is nice and the art really adds for a cozy vibe for a calm game to play and relax.
The addition of optional sound tracks is nice plus too.
The UI is simple to follow so it doesn't take long to find out what everything does (the item description showing up on hover was a good idea to show the items stats without overcrowing the screen ).
The catching circle becomes smaller when the fish is rare but the speed of the circle is slow so it doesn't add any real difficulty for the catch.
The only option of catching being the up scroll didn't fit well for me because as the main gameplay part i just beacame exaustive to scroll up ( either scrolling down or up would have helped a lot in this matter).