You never attack the other player. You send them monsters.

Gather by day, hold the line at night, and when holding isn't enough, spend a card to push monsters into a rival's rift instead of fighting them yourself. A survival / tower-defense / deckbuilding hybrid for 1–4 players.

Fits Steam's 300-character short-description limit.

Demonic Defense is four games running on one clock. You are a survivor in a cold open field with an axe, a campfire and a hand of cards. By day you chop, mine and build. At night the rifts open and the legion comes. The fire has to be fed or you freeze. The walls have to hold or you lose. And the whole time, up to three other players are doing the same thing in their own arenas — and every attack card you own points at them. There is no duel in this game. What you do instead is spend a card to push monsters out of their rift, in their arena, on their night. Cast at range for mana and the monsters arrive right now; walk to your own fire and burn the card instead and it costs heat, it's exhausted for good, it's stronger, and its monsters queue into their next night's legion. Every card in your hand is two decisions, and you cannot make both.