The steampunk zombie survival RTS They are Billions has become a sensation over the new year break. You build bases, suck resources out of the terrain nearby, and then produce as many soldiers as you can to withstand the increasingly fervent attentions of the zombie hordes nearby. Instead of hunting down an enemy base, all you have to do is survive to win. Sounds easy, doesn't it? It's not. It's horribly, horribly hard.
As the game kicked my ass repeatedly earlier today, I was reminded of a few different games that have toyed with this formula before. It looks like an RTS, thanks to the base building and unit production, but plays like a tower defence game. Here are a few other good games that explore this curious in-between space, mainly by throwing thousands of bad guys at you.
StarCraft 2: Wings of Liberty
If you want to hold off hordes of enemies as they run riot through your base, then the Terran vs. Zerg singleplayer missions in StarCraft 2: Wings of Liberty are a good choice. In Haven's Fall the Zerg move to infest human settlements as your Terran army tries to stop them. In Outbreak you start surrounded by zombified settlements that vomit out hordes of aliens every time night falls—sound familiar? StarCraft 2 marines look pretty similar to your basic gun troops in They are Billions, and TaB's watchtowers are basically StarCraft 2 bunkers.
Desktop Tower Defense
There is a strong tower defence element to They are Billions. Waves of creeps attack from different directions and mindlessly throw themselves against your defences until you or they are toast. Most tower defence games, like Defense Grid: The Awakening, funnel creeps into a set path that you cover with gun turrets. Desktop Tower Defense and They are Billions share a more open format. In both games you funnel the creeps into kill zones using the most efficient unit/tower placement you can invent. DTD has an advantage because it's free and you can play it in your browser.
Revenge of the Titans
Revenge of the Titans features giant city-wrecking Pac Man ghosts instead of zombies but, deep down, they hate the living all the same. This wave defence game has a much more developed resource system than Desktop Tower Defense, and you can place buildings with a bit more freedom than games like Defense Grid. Plus it has satisfying lasers that you can control with your cursor.
Another RTS about fending off thousands of enemies at once, Infested Planet sets your desperate last stand on a luminous neon world swarming with hundreds of alien creatures. You command a squad of five marines on a desperate mission to find a chokepoint and throw down some turrets. If you hold off the horde long enough you can start to spend resources and upgrade your squad's weapons. Look out for the hives nearby—they spawn increasingly tricky monsters as you fight through the campaign.
Project Zomboid is a survival game rather than a RTS game, but you're still gathering resources, building defences and fending off massive hordes of zombies. Death is inevitable, but it's the horrible, lingering journey full of disease and suffering that counts. Project Zomboid has been receiving new features since its Early Access debut in 2013, and has evolved into a deep, clever sandbox game that, like They are Billions, will kill you ruthlessly over and over.