Build a dungeon and punish trespassers
War for the Overworld puts you on the villain's side of the usual dungeon crawl. You dig tunnels and chambers beneath the overworld, then fill them with rooms, traps, defences and minions. Heroes come down to explore and take your stuff, so your layout and your defences decide whether they walk out rich or get taught the price of trespassing. The Veins of Evil give you over sixty rooms, spells, potions, rituals, defences and constructs to pick from as you go, which is where the sandbox feel comes from: two players can build very different dungeons from the same toolbox. Richard Ridings narrates the whole thing as the voice of evil, and the tone leans into dark comedy rather than grim horror.
Playing together
Multiplayer and Online PvP are listed, so your group can face each other instead of only fighting the AI. The six game modes are Campaign, Skirmish, Scenarios, Multiplayer, Survival and My Pet Dungeon, with a free two-level demo of My Pet Dungeon included in the base game. Skirmish and Multiplayer are the natural picks for a group that wants to dig in, build up and attack each other; Survival suits a shared challenge against waves; Campaign and Scenarios are more about working through set situations. My Pet Dungeon is the sandbox-flavoured mode for building without a fixed script.
Before you start
There is a Map Editor with scripting support, and custom maps go to the Steam Workshop, so your group can make and share its own scenarios. Dozens of mutators let you change the rules themselves, which is useful if you want faster games, stranger conditions or a house rule baked in. The game has been patched and rebalanced since launch, so expect the current build rather than the launch version. It is an RTS and management game at heart: you are digging, placing rooms and directing minions, not controlling a single hero through a dungeon.