3,856 articles
Ōkami (大神)
Ōkami (大神) is Capcom's 2006 PlayStation 2 action-adventure by Clover Studio, directed by Hideki Kamiya, starring the wolf sun goddess Amaterasu, whose Celestial Brush mechanic and sumi-e art style define it; an HD version and a Kamiya-led Clovers sequel announced in 2024 followed.
Old School RuneScape
Old School RuneScape (OSRS) is Jagex's 2013 MMORPG restored from an August 2007 backup of RuneScape 2, with 23 skills, 0.6-second game ticks, 75%-threshold player polls, Ironman modes, and the Sailing skill added in 2025.
Omori (video game)
Omori (OMORI) is a 2020 psychological horror RPG by OMOCAT, LLC, inspired by EarthBound and Undertale, funded on Kickstarter in 2014, released December 25, 2020 on Steam, with a turn-based emotion-system combat and about 2.3–2.9 million estimated Steam sales.
OMSI 2
OMSI 2 (OMSI 2: Steam Edition) is a 2013 Windows omnibus simulator by MR-Software GbR and Aerosoft, simulating Berlin-Spandau bus driving in 1986-1994 with deep bus systems, modding, and 120 DLC add-ons.
Once Human (video game)
Once Human (七日世界) is a free-to-play New Weird post-apocalyptic open-world survival game by Starry Studio and NetEase Games, launched on PC July 9, 2024, mobile April 2025, and PS5/Xbox August 25, 2026, with seasonal scenarios and Stardust-themed Deviant monsters.
Once Upon a Katamari
Once Upon a Katamari (ワンス・アポン・ア・塊魂) is a 2025 puzzle action game by RENGAME and Bandai Namco, the first new Katamari Damacy entry in 14 years, released October 23-24, 2025 for Switch, PS5, Xbox Series X|S, and Steam, with time-travel levels, cousin customization, and KatamariBall multiplayer.
One Piece: Pirate Warriors 4
One Piece: Pirate Warriors 4 (ONE PIECE 海賊無双4) is a 2020 musou action game by Koei Tecmo, the fourth in the One Piece-based Pirate Warriors series.
Onegai AiPri
Onegai AiPri (おねがいアイプリ) is the 2026 Pretty Series arcade game and anime by Takara Tomy Arts and syn Sophia, successor to Himitsu no AiPri, featuring card-moving rhythm lives, Buzzrium Change, and the linked AiPri Verse cabinet.
Oni (video game)
Oni is a third-person action game released in January 2001 for Windows, Macintosh, and PlayStation 2 by Bungie West, Bungie's satellite studio, combining shooting with anime-inspired hand-to-hand combat.
Onimusha (鬼武者)
Onimusha (鬼武者) is Capcom's swordplay action game series of Oni-powered warriors fighting the demonic Genma, launched in 2001 with Warlords, totaling 7.9 million sales by 2011, and revived in 2026 with Way of the Sword starring Miyamoto Musashi.
Onimusha: Warlords
Onimusha: Warlords is a 2001 survival horror action-adventure game by Capcom for the PlayStation 2, in which the samurai Samanosuke Akechi rescues Princess Yuki from demons.
Onimusha: Way of the Sword
Onimusha: Way of the Sword (鬼武者 Way of the Sword) is Capcom's 2026 swordplay action game, the first new Onimusha in over 20 years, starring Miyamoto Musashi fighting Genma in early Edo-period Kyoto on PS5, Xbox Series X|S, and PC.
Oninaki (鬼ノ哭ク邦)
Oninaki (鬼ノ哭ク邦) is a 2019 action RPG by Tokyo RPG Factory and Square Enix, its third game and first action title, following Watcher Kagachi through Daemon-based hack-and-slash combat; Metascore 69.
Online game
Online game: a video game played over a network, also called networked or multiplayer gaming. Spans postal and telegraph chess, BBS and MUD games, CompuServe's MegaWars (1982), MMORPGs like World of Warcraft, Xbox Live (2002), and mobile titles, built on client-server or peer-to-peer architectures.
Ontos (video game)
Ontos (ONTOS) is an upcoming 2027 sci-fi mystery immersive sim by Frictional Games, spiritual successor to Soma, set on the moon hotel Samsara; player character Aditi Amani, Stellan Skarsgård in cast, published with Kepler Interactive.
Open world
Open world (also sandbox) game design: players freely roam a large virtual world and choose when to pursue objectives. Traces to Colossal Cave Adventure (1976) and Elite (1984); GTA III (2001) defined the 3D form; market projected at $67.26B by 2035.
OpenTTD
OpenTTD is a free, open source (GPLv2) transport simulation game reimplementing Chris Sawyer's 1995 Transport Tycoon Deluxe, begun by Ludvig Strigeus in 2002, released 2004, with multiplayer, larger maps, and NewGRF modding; since March 2026 on Steam it ships only in a $9.99 bundle with Atari's TTD re-release.
Orbitals (video game)
Orbitals is a two-player co-op puzzle-adventure game by Tokyo studio Shapefarm, released as a Nintendo Switch 2 exclusive on September 3, 2026, with no single-player mode.
Order of the Sinking Star
Order of the Sinking Star (沉星之序) is a 2026 puzzle adventure by Thekla, Inc., directed by Jonathan Blow, published by Arc Games for PC, Switch 2, and PS5 at $29.99, with 1,000+ hand-crafted puzzles in a four-world Sokoban 'supercollider' design.
Ori and the Blind Forest
Ori and the Blind Forest (Definitive Edition) is a 2015 Metroidvania platformer by Moon Studios, published by Microsoft, for Xbox One, PC, and Switch; Metascore 88, energy-orb save system, over 10 million copies sold.
Ori and the Will of the Wisps
Ori and the Will of the Wisps (Ori 2) is Moon Studios' 2020 Unity metroidvania sequel to Ori and the Blind Forest, adding melee combat, spirit shards, autosave, and quests; Metacritic 90, two million players by July 2020, Xbox Game of the Year 2020.
Oro (Street Fighter)
Oro is a Street Fighter character, a one-armed hermit first appearing in Street Fighter III: New Generation and returning as Season 5 DLC in Street Fighter V on August 16, 2021, with Double Jump and Tengu Stone moves.
Osu!
Osu! is a free-to-win, open-source rhythm game by peppy, publicly released September 17, 2007, with four game modes (osu!, taiko, catch, mania), community beatmaps, and pp-based global ranking.
Our princess is in another castle!
"Our princess is in another castle!" is the English on-screen message from Super Mario Bros. (1985, Famicom/NES), delivered by a Mushroom Retainer (Kinopio) after seven of eight castle levels; a gaming meme, trope name, and Nintendo self-reference.
Out of Words
Out of Words: upcoming 2D co-op platformer adventure by Kong Orange, WiredFly, and Morten Søndergaard, published by Epic Games. Stop-motion handcrafted world Vokabulantis; Kurt and Karla seek lost voices; delayed to early 2027.
Out Run
Out Run (アウトラン) is Sega's 1986 Yu Suzuki arcade driving game with a Ferrari Testarossa, 15 branching courses, five endings, and Kawaguchi's soundtrack; 30,000 cabinets made it Sega's bestselling 1980s arcade game.
Outer Wilds
Outer Wilds is a 2019 open-world mystery game by Mobius Digital and Annapurna Interactive: a 22-minute time-loop solar system where knowledge is the only progression. Won BAFTA 2020 Best Game; expansion Echoes of the Eye (2021).
Outlast
Outlast (2013) is a first-person survival horror game by Montreal's Red Barrels; a journalist with a camcorder explores Mount Massive Asylum with no combat, night-vision batteries, and the Whistleblower DLC.
Outlast 2
Outlast 2 (Red Barrels, April 25, 2017) is a survival horror game starring cameraman Blake Langermann, who searches the Arizona cult town of Temple Gate for his wife Lynn; no weapons, camcorder night vision, Metascore 75.
Outriders (video game)
Outriders (OUTRIDERS) is a 2021 third-person co-op looter shooter RPG by People Can Fly and Square Enix, set on Enoch, with four classes and the Worldslayer expansion (June 2022); Steam peak 125,123 players.