65%Strong matchAttack of the Earthlings
85%31385% positive reviews, Very Positive across 313 reviews·Turn-Based Strategy · Dark Humor
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Aliens invade Paperverse! Protect the terrorized civilians and discover the source of the alien threat in this minimalist game of battlefield tactics and global defense strategy.
Book of Aliens
Steam
Book of Aliens’ action takes place during a global crisis. Earth is threatened by an alien invasion originating from below the planet’s surface. Your mission is to lead a supranational agency of scientists and military agents in a desperate but valiant fight to understand the alien agenda and thwart it. The game is currently in early development. The screenshots shown are from one of our in-house prototypes and they might not reflect the actual look of the final game. While we can’t reveal a lot of details just yet, you can expect:

unique gameplay mechanics that make the game simple to play yet strategically challenging and difficult to master

a game that respects your time and can be enjoyed in both short and long gameplay sessions

high replayability thanks to randomized levels and card-based mechanics

beautiful paper pop-up book stylized graphics Be sure to wishlist the game to be notified when it is released.


Book of Aliens is the upcoming second installment in Return 2 Games, a series of unique mid-core games inspired by the golden days of PC gaming. Each R2G title is a tribute to a single hit game from the ’90s: a reimagining of a single universal story for a brand-new audience, using modern means and innovative, often vastly simplified gameplay mechanics.

Book of Aliens is developed as a tribute to MicroProse’ UFO: Enemy Unknown. If you want to learn more about Return 2 Games or support us in the development of the series, visit the Supporter Pack store page: Book of Demons, the first part in the series is already here, be sure to check it out as it includes a free demo. Also, be sure to check out Book of Demons: HELLCARD, a Book of Demons co-op roguelike deckbuilder that’s also in the works:
Steam data © 2026 Valve Corporation. Trademarks are property of their respective owners.
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The best games like Book of Aliens are Attack of the Earthlings, Alien Shooter: Revisited, Xenonauts 2, Xenonauts, and Shattered Planet.
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