It is a great game. I like the basic mechanics of the game, but as far as I'm concerned, this is pretty much an AFK game. When you're not fishing, collecting snails, whacking seals or whatever you choose to spend your time on, you basically wait for your exp and/or money pile to increase. So what I think could be a good idea here would be a few minigames.
You play them and unlock hats as you play them. Those hats could be used for small things like fishing, whale farming, burger cooking and so on. A fishing hat could give you a small experience boost when fishing. A whale farming hat could give you a small amount of experience when farming whales. A burger cooking hat could give you a small percent chance to cook another free burger.
The idea here is simple. During these minigames you get pengi points. You can spend those in a pengi point shop and purchase the special hats, money, experience or lost goldfish/sea snails.
 "Pingy the Ping Idle RPG"){kind=icon}