Press the go button until You find something, (the screen will turn black), Then click the Thing you find until his health is 0, than repeat, the common (gobo) gives you +0.1 click Damage per common owned, the legendary (ghost) gives you +1 click Damage per legendary owned, And the mythical (cat) gives you +5 Damage per click per owned.
This game is highly based on Pokemon, please note there are a few bugs, please tell me about any bugs you find and I will try to fix it.