Level

The levels are something very important in the game, it depends of the level which monsters, decorations, and machines you can buy, and different islands are unlocked when you have a higher level.

Monsters
There is a monster level too, it depends of the level, to which adult island can the monsters go, the amount of money that you obtain with that monster depends of the level too, and the highest the monster level is, the higher are the posibilities of getting a many elemented monster.