"Farmed" (cleared obstacles) on a lot of islands, found 100 Crystals and completed the bridge to get Spike the Stegasarus. Mission Accomplished! Then had a fun taking Spike around to islands because he eats blueberries (short growing time), clears all obstacles (grass, trees, rocks), and uses his tail to whack stuff which is a fun animation to watch.
I got lucky and found Malika the Black Leopard so the Game Play Shift is to now raise coins because OMG that kitty requires an expensive house - like 71,560 coins worth of expensive.
So far, I've found playing the Gorilla Match 3 game (2 blueberies, always win, get 70 coins), crafting ladders (sells for 200 coin each), selling blackberries (45 minute grow time, get 4, sell for 10 each), and cooking (2 hours, 4 blueberries + 1 flour) and selling (40 coin each) blueberry treats to be the cost/time effect ways of raising money. At Level 16, the animal houses I have built spit out coins faily often throughout the day, so checking in on the game every now and then is worth a few minutes of time.
Did explore a few more islands and ended up rescuing the Cougar and the Beaver - neither of which I can bring home since Malika is still sitting on the dock waiting for me to earn enough to build its house.
And it looks like the Cougar lives in the same neighborhood, as that house is going to cost 58,530 coin. The Beaver apparantly lives on the hill on the rich side of the tracks as that house is going to cost 90,330 coin.
Housing costs vary depending what you've done in the game, so if your animal homes are less expensive, celebrate your good fortune. :)