Similar to ホームメイドスイートピー

Old Man's Journey

Osu!

Otometeki Koi Kakumei Love Revo!!

Oni (video game)

Oninaki

Onimusha

Bail or Jail

Observer (video game)

Operation Flashpoint: Cold War Crisis

Operation Flashpoint: Dragon Rising

Half-Life: Opposing Force

Omoide ni Kawaru Kimi: Memories Off

Omori (video game)

Ori and the Will of the Wisps

Ori and the Blind Forest