I think Prope should, but they should do a better job advertising the game to western audiences.
What changes should Prope make and which features does Prope need to keep?

Um....more fish and natural baits

It'd be great if they did. I love all their games so far. Still hoping Rodea Sky Soldier gets released.

Prope is just a developer not a publisher. For a sequel to happen some publisher would have to agree to it - which is possible. It sold decent in Japan and would no doubt sell better on WiiU (with a growing base) I believe Namco published in Japan. XSeed published in NA and they have zero marketing budget. So someone bigger would have to pick this up for any chance of real marketing.