Best Sci-Fi Games Over 100 Hours Long

Many sci-fi games claim they have lots of things to do, but only a few actually keep players busy for more than one hundred hours. To see everything these games offer, a player must be ready to spend weeks or months exploring every dark corner of space. In some of these games, a player could spend fifty hours just learning to build and fly a spaceship.

Many of these games give players freedom to explore and do their own thing instead of rigid paths. If the time commitment sounds too intimidating, that is part of the appeal. For players who enjoy long journeys and big galaxies that do not rush them out, these games offer exactly that. The completionist times in this list are from HowLongToBeat.

No Man’s Sky

Completionist Time: 154 Hours

• Explore a procedurally generated world with billions of planets.
• Progress depends on how much exploration, discovery, and upgrading a player chooses to do.

No Man’s Sky is an open-ended game where the goal is essentially to stay for as long as possible and not exactly to finish off everything. It’s built around a huge procedurally generated universe where every star system, planet, creature, and landmark is created by algorithms rather than being hand-designed. That means there isn’t a small, fixed amount of world to see.

There are countless places a player might visit and things to discover, and players spend time scanning creatures, cataloging flora and fauna, finding rare items, and travelling huge distances across the galaxy.

EVE Online

Completionist Time: 746 – 3333 Hours

• Massive universe where players take part in trading, combat, exploration, and politics alongside thousands of others in real time.
• Running corporations and fighting in wars that unfold over months or even years.

The concept of finishing EVE Online is almost impossible, which is why the completionist time is so wide and high. This game is like a second life for many of its most dedicated players. The most important thing to understand about this game is that almost every single element, from the economy to the politics, is entirely player-driven. Unlike many other online games where the player characters are mere heroes in a virtual landscape, in EVE, players are the fundamental building blocks of the universe, and their actions carry consequences.

To become truly powerful, players have to train complex skill trees that take months. This is why EVE Online is one of the few classic games that players just can’t drop, even after many years. The social world is run by player groups called Corporations and big alliances. These groups constantly spy on each other, control trade, and start huge, often shocking wars. When a massive space battle happens, it is not scripted; it’s a real event caused by players fighting over territory or trying to ruin each other’s businesses.

Elite Dangerous

Completionist Time: 677 Hours

• The game is a flight simulator and sandbox set in a 1:1 scale recreation of the Milky Way galaxy, featuring 400 billion star systems.
• Players take on jobs like trading, bounty hunting, deep space exploration over massive distances, and fighting against the mysterious alien race.

It is hard to believe, but this game rebuilds the entire Milky Way galaxy exactly to scale. Elite Dangerous is a space flight simulation where the player can fly inside a 1:1 model of our home galaxy. This massive scale is why the completion time is so high. A player must cover huge distances to see even a tiny part of what the game offers, flying far away from the main areas of human space known as The Bubble.

The game is so big that flying long distances is a serious time sink that requires careful planning and a lot of management. To master all the ship upgrades, top-level missions, and deep exploration takes many hundreds of hours of focused flight time.

Stellaris

Completionist Time: 369 Hours

• It’s a 4X strategy game where players manage a civilization’s growth into a massive galactic empire.
• The main time sinks are mastering the deep economic and research systems, managing planets across a huge map, and surviving large, galaxy-threatening crises.

Instead of flying a single spaceship, Stellaris makes the player the absolute boss of an entire galactic civilization. The main goal is to take a civilization that has just learned how to go to space and turn it into a powerful, galaxy-spanning empire. This is not just a sci-fi space exploration game; it’s a strategy game that requires patience and planning.

For players who are willing to go all the way, from meeting the first aliens to facing threats that could destroy the galaxy, they could spend around 369 hours. Because the game has several research paths, trait combinations, and control over dozens of star systems, it can be overwhelming for even experienced players.

Fallout: New Vegas

Completionist Time: 131 Hours

• The huge playtime comes from the extreme branching paths, which force players to complete the long, unique quest lines for the four competing major factions to see all content.
• This is a massive open-world RPG set in the post-nuclear Mojave Desert, where the player controls the fate of the region.

What makes Fallout: New Vegas so long and replayable is the incredible depth of choice and how much a player’s decisions change the story. The long completion time is mostly due to the faction system. The main story is important, but it is really just a backdrop for the war between four major powers, including the soldiers of the New California Republic (NCR), the brutal, slave-owning army of Caesar’s Legion, the mysterious tech-genius Mr. House, and the final choice of whether to go alone with the help of the Yes Man computer.

Choosing one side means players become permanent enemies with the others, which locks off huge amounts of content and side quests. To truly see everything the Mojave wasteland has to offer, players have to spend time trying out different choices and seeing the outcomes.

Starfield

Completionist Time: 148 Hours

• Players explore a galaxy with over 1,000 planets, focusing on space travel, resource gathering, and uncovering ancient alien secrets.
• The game has deep systems for building custom spaceships, managing planetary outposts, and leveling up a complex skill tree.

Starfield is a very long game because it is kind of like a “forever game” with a massive amount of things to do. The reason it takes nearly 150 hours to complete is due to the sheer volume of handcrafted and procedural content. While the main story might only take 30 hours, a completionist must finish all major faction questlines, including the United Colonies, the Freestar Collective, Ryujin Industries, and the Crimson Fleet. Each of these stories is long and has its own set of missions and rewards.

Beyond the stories, the Survey mechanic is another thing that eats time. To fully complete Starfield, a player has to scan every planet. And this means landing on different worlds to find and scan every plant, animal, and mineral. As if that’s not enough, building a perfect ship and a network of outposts to gather rare resources also adds many hours to the clock.

Cyberpunk 2077

Completionist Time: 107 Hours

• A first-person shooter where a mercenary takes on dangerous jobs to survive in a high-tech, dark future.
• Players navigate complex relationships and political power struggles that determine which of the multiple endings they will see.

For those who want to strictly focus on the main campaign of Cyberpunk 2077, they can finish it in roughly 25 to 30 hours. However, the game is designed to be long through its massive web of optional content that directly affects the world and a player’s fate. Players will have to complete many gigs.

Cyberpunk 2077 is one of those games where a huge portion of the core experience is in the side quests. And completing these side content pushes the 30-hour run toward a 60 or 70-hour experience. However, the game officially stretches past 100 hours for completionists because the side content is not just filler; it actually includes massive, multi-hour character arcs for characters like Panam Palmer and Judy Alvarez.

Satisfactory

Completionist Time: 228 Hours

• This is a factory-building game focused on designing and optimizing massive automated production lines.
• Progress largely depends on gradually expanding, refining layouts, and solving efficiency problems that players set for themselves.

When it comes to completing an open-world factory building sim like Satisfactory, being 100 hours deep is barely scratching the surface. In fact, 100 hours might not be enough to complete the main story alone. One of the main reasons Satisfactory is so long is because of the Project Assembly phases. To finish the game, you must build a massive Space Elevator and send special parts up to a space station.

There are about five phases in total. The first phase is simple and takes only a few hours. However, each new phase is much harder than the last. By the time a player reaches the final phase, they would have spent a good amount of time.

X4: Foundations

Completionist Time: 419 Hours

• Simulates a living space economy where ships, stations, and factions operate independently of the player.
• Building an empire, managing fleets, and influencing the galaxy takes time.

X4: Foundations is not just another space sim where players build and fly the best spaceships; it’s actually built on a real economy where every single ship and station is built from actual resources. The game is kind of slow because players start as a single pilot with just one ship. To grow into a leader who owns fleets and space stations, they have to learn very hard systems.

Players have to manage pilots, engage in trade activities, and build massive ships. Building just one part of a spaceship can take time, and a large ship might have dozens of parts. Players also spend a great deal of time because they are trying to take over the entire galaxy or wipe out the enemy machine race known as the Xenon.

Death Stranding 2: On The Beach

Completionist Time: 115 Hours

• Sam travels across large open worlds set in Australia and Mexico.
• Deliver cargo, rebuild infrastructure, and link isolated colonies while managing terrain, weather, and enemies.

Death Stranding 2: On The Beach and the original game are roughly about the same length, but the sequel has about two or three more chapters. Death Stranding 2: On The Beach has two maps (Australia and Mexico) for players to explore, as they try to increase their Connection Levels to five stars.

Because there are about 42 different facilities to connect, reaching the maximum 5-star level with everyone is one of the main reasons a completionist run takes about 115 to 118 hours. It also has to be said that there’s a way the environment slows players down on purpose. The game has dynamic weather and disasters like sandstorms that can destroy a player’s path or damage their cargo. So they have to stop and plan their route carefully or wait for the weather to clear.