Anyone who considers themselves a big fan of science fiction in media knows how deep most entries in the genre run. These long stories showcased in books and movies have ways of enthralling viewers into the story, keeping them hooked through the plot's nooks and crannies.

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Science fiction in video games is no different, except for the fact players can feel like they are a part of the story instead of just viewing it. These journies can be thrilling to go on not only because of the fun gameplay and enriching stories but because of how long they last. For those looking for a long sci-fi experience, there are quite a few games to choose from.

10 Star Wars Knights Of The Old Republic II: The Sith Lords (31 Hours)

Gameplay of Star Wars Knights Of The Old Republic II

Obsidian Entertainment is known for making great games, and its first-ever game was no different. Star Wars Knights of the Old Republic II: The Sith Lords, released in 2004, was a sequel to a game that BioWare developed and won many awards for. Obsidian pulled it off, however, and did so by implementing around 31 hours of story. The Star Wars RPG takes place five years after the first game focuses on The Exile, a Jedi Knight who was exiled but later finds the person who exiled them and is tasked to find other soldiers to fight against the Sith.

9 Horizon Zero Dawn (32 Hours)

Horizon Zero Dawn gameplay

Guerilla Games had never created a role-playing game before, but their first attempt may be one of the greatest games released on the PlayStation 4. Horizon Zero Dawn, which has an estimated 32-hour campaign, follows a hunter named Aloy. In a world filled with aggressive machines, she is on the hunt to find out what happened to the world that got it to this point. The open-world game has plenty for players to explore, with landmarks to discover and side quests to complete while on the main path.

8 Phantasy Star II (33 Hours)

Phantasy Star II gameplay

Going back in time to the Sega Genesis era, Sega developed the second installment of their classic RPG Phantasy Star. Produced by Yuji Naka before the birth of Sonic the Hedgehog, Phantasy Star II takes place 1,000 years after the original.

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The player is Rolf, a confident and somewhat unlikeable government agent, sets off with friends to find out the root of malfunctioning occurring on the planet Mota, otherwise known as the Mother Brain. It is estimated that the game's main quest line takes 33 hours to complete.

7 Rogue Galaxy (38 Hours)

Rogue Galaxy gameplay

Yet another RPG, Rogue Galaxy is a science fiction game developed by Level-5 and published by Sony. The game took three years to develop and was considered to be a potential competitor with RPG giants Final Fantasy and Dragon Quest. Although it never reached those levels, Rogue Galaxy did have a substantial story mode that lasted about 38 hours. The game follows Jaster Rogue, an agricultural worker who is becomes involved in a global conflict. Eventually, he learns that only he could save the galaxy as he knew it.

6 Fallout: New Vegas (38.5 Hours)

Fallout New Vegas promotional image

Another game by Obsidian Entertainment, Fallout: New Vegas is a spin-off of Bethesda's Fallout series and, despite not being a main-line game, is considered by some as the best in the series. The game takes place in the year 2281 in a region between Arizona, Nevada, and California. The open-world experience has players take on the role of Courier, who was delivering a package to the city of New Vegas but is robbed of the package and shot. The journey to hunt the robber down and more takes place over approximately 38.5 hours.

5 X-COM: UFO Defense (39.5 Hours)

X-COM UFO Defense gameplay

The XCOM video game series is highly-regarded as one of the most influential strategy game series of all-time. The first game came out in 1994 and was called X-COM: UFO Defense (or more universally known as UFO: Enemy Unknown). The player is a member of X-COM who is secretly looking to save Earth from any potential alien invasion. The game uses a real-time management system for players to dictate where the X-COM troops go using turn-based tactics in battle. Overall, the main game lasts around 39.5 hours.

4 Death Stranding (40.5 Hours)

Death Stranding gameplay

When Hideo Kojima went independent, many wondered how his first project would work out. What was created was at least a 40.5-hour adventure that left many in awe and confusion. Death Stranding stars Sam Bridges, a porter tasked with delivering supply cargo to various cities isolated around the post-apocalyptic United States.

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The player's tasks are to deliver these goods and add cities to a wireless communication network. Despite some confusion, critics praised the story while others criticized the gameplay as at times being tedious and boring.

3 Star Ocean: Till The End Of Time (45 Hours)

Star Ocean Till The End Of Time promotional image

Returning to role-playing games, one role-playing game that never gained steam in North America is Enix's Star Ocean. Its third game was the biggest of the series to date with 45 hours of the main story to get through. Star Ocean: Till the End of Time takes place 400 years after the second game. Players take on the role of Fayt Leingod who is on a quest to search for his family and his childhood friend, Sophia, after an attack by an unknown space military at the resort they were staying at.

2 BattleTech (54 Hours)

A battlemech in BattleTech

If X-COM: UFO Defense seemed long for a strategy game, BattleTech adds 14 and a half hours to have about 54 hours of the single-player campaign. A game by Harebrained Schemes, BattleTech started out as a Kickstarter and reached its goal within one hour of publishing. Taking place in the 3025 Succession Wars Era, where multiple powerful houses own battlemechs that are operated by MechWarriors. Players can choose which house they serve and can customize their array of battlemechs. The game is based on the board game Classic BattleTech.

1 Xenoblade Chronicle X (68.5 Hours)

Xenoblade Chronicles X gameplay

If looking for the longest sci-fi video game experience out there, Xenoblade Chronicles X is where to look. The story mode is estimated to be about 68.5 hours long. While the game is part of the Xeno series, it is considered separate from other Xenoblade Chronicles games. In the game, Earth has been destroyed by alien war. A ship called New Los Angeles with a handful of people on board lands on Mira, an uncharted planet. After being awoken from their hibernation pod, the player joins the BLADE and must protect NLA from more alien attacks.

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