This is a great game concept. Pressing and holding the Space Bar to "aim", and the same mechanic to reel in felt really good. I think the casting speed was a bit slow and I was waiting for the target to get to the fish a little too long.
The pixel art looks really good; maybe do something with different sized fish to do different point systems; and maybe make bigger fish take longer to reel back in and smaller fish taking less time but be worth a lot less points.
Great concept, great execution, some room to improve your designs.