It's extremely simple, and thanks to that easy to get into and enjoy. The Artwork is cute and fun, and the music adventurous and whimsical.
You simply click and hold the left mouse button to guide your mob of peasants on their adventures. Note, they really really aren't adventurers. They're peasants, they want to smash things and get loot, but are really really dumb. They'll often run into spikes and other nasty traps because they saw a vase they want to smash or some coins they want to pick up.
As such they can get all over the place as you increase your party in size. Thankfully you can upgrade them via outfits to transform them into pseudo-adventurers that are better armed than our yellow poncho clothed club swinging ones.
Not only that, but the peasant garb, and unlocked outfits can be upgraded and improved upon.
So head to your tavern, pick up a quest and click Dungeon to get started. The game is is time trial based, so the quicker you do things and better rewards you get. Although in many cases some quest rewards are so lucrative you really don't need to scrounge around wasting time smashing crates or looking for coins. Just rush through. Now while this does mean you miss out on bonus rewards and goodies, you can upgrade the Quest Rewards with level points. Further making them an even better option.
Sadly the dungeons aren't very random, and you can often get the same routes over and over. I do hope they add some procedurally generated versions, along with more quests.
So far it's fun, and considering the price it's well worth it in my opinion.