If you played much of the fine Warcraft III mod Night of the Dead, then The Red Solstice [official site] should look mighty familiar. That’s because it heavily draws inspiration from Night of the Dead, and one of Red Solstice’s leads worked on a NotD variant. If not: 1) you missed out; 2) I’ll explain.
The Red Solstice is a top-down tactical shooty action-RPG about scavenging supplies, completing missions, and gunning down alien hordes to survive hour-long missions in singleplayer and co-op modes. After one year on Steam Early Access, it has now properly launched.