Worship
From IdleOn MMO Wiki
Worship is a World 3 skill that Wizards will specialize in. It plays out through a Tower Defence minigame.
Place towers to fight off endless waves of mobs! Get far enough, and you'll unlock another place to play tower defence at! There are 6 places in total, with the 1st one being located at the Goblin map
You can either actively play the tower defence, or you can just 'auto' do it, and get rewards based on your best performance. This means you can play it as much as you want, but you won't get left behind if you only want to play it a few times!