You're referring to the highly-acclaimed action-adventure game, God of War II, developed by Santa Monica Studio and published by Sony Computer Entertainment. Released in 2007 for the PlayStation 2 console, God of War II is the sequel to the 2005 hit game, God of War.
Originally released in 2007, God of War 2 was a technical marvel. While most PS2 games fit on a standard 4.7GB DVD, Santa Monica Studio had to use a dual-layer DVD (holding roughly 8GB) to fit all the high-quality textures, cinematic cutscenes, and massive boss encounters like the Colossus of Rhodes.
Emulator: A compatible PS2 emulator (e.g., AetherSX2 or DamonPS2).
2. The "Trainer" or "Debug" Executable: Some rare 200MB files are not the full game, but a specific level-select demo or a debug executable ripped from a development HDD. These contain only the code and a single level. This is the closest to a true "exclusive."
While God of War: Chains of Olympus and Ghost of Sparta are different games, their PSP ISOs are genuinely 300MB–500MB. If you truly need a 200MB God of War experience, play Chains of Olympus on PPSSPP emulator with a Kratos skin pack.