Top similar games like 20 Days:

The Fermi Paradox is a choice-driven sci-fi narrative strategy game in which your decisions in one corner of the galaxy can upend entire civilizations in another. Guide species through millennia and help them explore the vastness of space, make contact and, perhaps, create harmony.

MatchyGotchy Z is a colorful digital pet game that combines idle clicker elements with a new take on pet-raising simulation: trainable personalities. All the nostalgia of those old virtual pets, fully adapted into a new desktop gaming experience.

Deep Space Miner is a short incremental mining game about unlocking powerful tools, upgrades, and game-changing procs. Explore planets, mine rare resources, evolve your gear, and grow stronger through a massive skill tree as you push deeper into the galaxy.

An idle incremental adventure in space! Mine asteroids while fighting off enemy AI drones. Build your own AI drones, mining lasers, helper drones and more. Collect hundreds of rewards and unlock a variety of features that will help your ultimate goal: making numbers go up (or sometimes down).

A sci-fi themed incremental game which allows you to expand your capitalistic empire across the galaxy! Hire mercenaries to pillage alien planets for resources, with the singular goal of making as much money as possible as quickly as possible! Totally not a playful commentary on real Terran society.

This sci-fi adventure brings you to command stations in the far corners of space. Casually make decisions and watch how well you can balance the needs of your station.

You were chosen for the Planet Keeper Program. Defend the planet in this retro-inspired incremental game. Upgrade our defenses, destroy our enemies, ensure our future.

Sublunar is a Sci-fi, Puzzle, Strategy game, where the goal is to convert settlements over to your faction, by performing missions and strategic upgrades, while fending off bandits and subsiding revolts.

The debt is a trap. DEBRISVERSE is a sci-fi incremental sim where you crush space debris for profit. Use roguelite upgrades to accelerate destruction and pay off your $100M debt. But this perfect workplace has a dark secret. Uncover the system's conspiracy across 7 unique endings.

Endless Sky is a 2D space trading and combat game inspired by the classic Escape Velocity series. Work your way up from a relatively wimpy shuttle, cargo ship, or fighter, to a highly upgraded and customized flagship or to a massive fleet of warships or freighters.

Enter the ambient world of Osmos: elegant, physics-based gameplay, dreamlike visuals, and a minimalist, electronic soundtrack. Your objective is to grow by absorbing other motes. Propel yourself by ejecting matter behind you. But be wise: ejecting matter also shrinks you. Relax - good things come to those who wait.

Will you use the gravity of the planet or jump through a black hole? It’s up to you. Set an angle, speed and just watch how unsuspecting colonists fly through the space hoping, that they won’t end up flat as a pancake on some meteorite. Puzzle game with unique story will put your brain to the test.

Destroy Aliens, earn Stars, upgrade EVERYTHING. Blast enemies, power up your ship, unlock stronger aliens, and watch your Stars soar.

A text-based, choice-driven adventure. Intrigue, trust, loyalty, luck, reflex... How high a position can you achieve in this medieval world?

Civilization was born from a chaotic star system and has been constantly tested in its development, from ancient civilizations to occupying the entire galaxy, which is long and dangerous.

Meet some aliens, make some money, and save the galaxy while you're at it!

Grow your fleet of space ships in this incremental space game. Extract wealth from the asteroids and stations, unlock upgrades to find synergies, defend against pirates, and unlock [REDACTED]. Pin to your desktop and watch your empire grow while you do "more important" things.

Lightracer Spark is a Sci-Fi Narrative game. You are an amender from a high civilization, descending to various extraterrestrial worlds. Guide living beings to prosperity, or nip a spark in the bud. Accumulate strength through choices and strategies to grasp the rise and fall of all civilizations.

You are the newly appointed Judge in the Stone Age trying to keep a chaotic island from falling apart. Listen to bizarre testimonies while balancing absurd laws and deadly politics. Pass judgment, shape the island's fate, and uncover the truth behind your father's mysterious disappearance.

Forgotten Stars is a tactical RPG where you recruit your own crew of space pirates. Plunder your opponents, build bonds with your crew, and embark on your journey through the darkest corners of space.

Space Colonizers is a simulation and strategy idle game of Sci-Fi adventure theme. To explore more planets and meet cute aliens, you have to constantly install parts and upgrade spacecraft.

Lazy Galaxy 2 is an idle/clicker game with base-building and RTS elements. Lead an evil (albeit lazy) alien race to conquer the universe! Expand your base, fight vicious foes, and conquer the galaxies. Acquire combat experience and convert into candy, the most precious alien resource!

Real-time strategy battles in amazing sci-fi worlds! Command brave soldiers, mighty mechas and powerful aliens to face the greatest challenges in hostile alien worlds. The galaxy needs you!

Add Astra is a math game about racing, and a racing game about math, developed by Coincidence. You’re the best arithmetech racer on Earth. But what about everywhere else?

The Rebel Space Admiral is an idler/ clicker game about space exploration with battles, trade, base building, planet invasions and science research. Fight your way through hundreds of star systems, meet aliens, find powerful artifacts and defeat an ancient evil before it purges the galaxy.

Tasked with commanding of one of the most challenging sectors of the galaxy, the future of the Alexandria IV space station depends on your diplomatic and strategic capabilities. How far will you go to prevent a war? A space opera visual novel by J.M. Beraldo.

Mini Gal4Xy is a light strategy game set in space.

Beware Planet Earth! is a beguiling mix of classic tower defense and time management coming to PC via Steam for the first time. Save your cows from the Martian invasion by building an effective defense using towers, traps and objects, and also by firing your Zapper directly at the invading force of little green men!

You are the Evil Emperor's only daughter, but can you claim the throne? Raise stats, make deals, appoint advisors, and scheme your way through the Imperial Election - unless an assassin gets you first. Rule the galaxy or die trying!

Amidst powerful alien empires, you are among the first humans in this corner of the procedurally generated galaxy. Trade and explore. With no combat, your success hinges on mastering complex alien economies and navigating intricate politics. Can you carve out a place for humanity in the cosmos?

We have built a mini universe with real physics basis, simulation and imagination. The game uses realistic environments and models to tell a story of a mini universe.

In this 2D ARPG,you will play as a human who has been kidnapped by alien poachers. After being rescued by the Galactic Animal Protection Organization, you choose to join and embark on an adventure across the galaxy.

Holding Pattern is a minimal incremental game about protecting your galaxy from invaders. Defeat enemies, collect cash and purchase powerful moons and abilities! What crazy builds will you discover? Play either incremental or roguelike modes to put your skills to the test!

A Strategic Empire Collapser. As The Authority. Manage a living galaxy, and plan large-scale actions according to your needs. Collapse governments, inflame rebellions, seed new factions, and sacrifice your own. All for purposes grander than any Empire could hold.

An extremely difficult strategy game focused on stealth mode. Your objective is to lead the cows on their escape through the spaceship. Go from hiding to hiding so as not to be seen by the aliens and be patient with the granny cow. Are you qualified to fulfill this mission?