Island master! Trophy in Hell Yeah! Wrath of the Dead Rabbit
Open a gift sent from the Island "When you're the Boss, you have 365 birthdays."
How to unlock Island master!
After you defeat 10 monsters, a screen will appear telling you that the Island is now open. Visit the island and you will be taken through a tutorial on how the island works. After going through the tutorial, assign your monsters to work at any of the 4 available locations. Now you will want to leave the island and continue with your main story.
After playing for an hour or so, wait until you see the floppy disc flashing in the corner, signifying your game is saving and exit to the main menu. The menu option that was once labelled ???? is now available under "Island", choose this. If you see an exclamation mark over your chosen location for your monsters to work, enter that location. The exclamation mark means there is something available there. If nothing is available yet, set more monsters to work and return to your main game. Play for a while longer then come back.
Once you have a gift available at a location, select it on the screen then press to have the postman send it to your main game. Finish whatever you need to do on the Island then return to your main game. Upon returning a screen will appear asking you to open the gift that was sent by the postman. Just press again to accept. The trophy will unlock after accepting the gift.