(Via the Steam store page.)

About This Game
CastleMiner Z is an online coop survival horror game in a block based environment. Travel with your friends in a huge, ever-changing world and craft modern weapons to defend yourself from dragons and the zombie horde!

Game Play
CastleMiner Z is an infinite world filled with deep places to explore, and horrifying monsters to slay. Build structures out of blocks, craft weapons and tools from raw materials, and explore the vast and frightening world around you.
Play by yourself or online with friends in any of these exciting game modes:

Endurance Mode: There are tales of a place beyond the mountains where Hell itself has torn through. How far can you get before you succumb to the zombies, dragons, skeletons, or other enemies that thirst for your blood? Run, fight, and sneak your way across dry deserts, snowy mountains, and icy expanses on your quest to vanquish the ultimate guardians of the abyss. In Endurance Mode, the world is randomized each game and the death of your party is permanent.
Survival Mode: If you enjoy Endurance, but would rather build permanent structures and defenses, Survival Mode is where you’ll spend your time.
Creative Mode: With simplified crafting and the ability to adjust or eliminate the enemy threat, Creative Mode is a great place to build vast structures in peace.
Dragon Survival Mode: For those who like their trophies big and their hair singed and smoking, Dragon Survival Mode brings you up close and personal with wave after wave of the biggest, meanest, scaliest brutes in the game.

Worlds can be saved in any game mode (except endurance) so try building a castle with enemies turned off, then grabbing some friends and loading it up with enemies turned on!