Another idea here to help players and you guys out. A trade system for items, eggs, decorations, and armor. People can set up what they want to trade and sell it for in game money, or set it up for a list of items they want in return, including star gems. Trading items for gems is a good idea too, benefits the players and you guys a lot. There are always people who never pay into a f2p game for various reasons, but they need gems too. A trade system where they can offer a shiny egg for star gems allows them to get gems...and means someone had to buy gems from you to buy that egg! Turn the non payers into people providing income for you, and give players a chance to trade for gems and other items. Everyone wins!
I like the game so far, hoping for more monsters to be added and more areas. Idea for game that may be interesting is friend breeding of monsters. Each person selects one monster and they breed, each gets an egg. Perhaps a service people can offer to other players with it, where they offer one of their beasts for breeding, in exchange for money or items. People want more breeding options, and it'll open up some people who have terrible luck with eggs to someone else's good luck.