Similar to ファイナルエクセリオン

Empire Earth (video game)

Enlisted (video game)

The Awesome Adventures of Captain Spirit

Orbiter (simulator)

OpenTTD

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Otometeki Koi Kakumei Love Revo!!

Oni (video game)

Off (video game)

Operation Flashpoint: Cold War Crisis

Operation Flashpoint: Dragon Rising

Half-Life: Opposing Force