The game was originally released for the Wii console in 2011. A Wii ISO file is a digital copy of the game, which can be played on a computer using a Wii emulator or on a Wii console using a homebrew loader.
For players running the game on the Dolphin Emulator or a modded Wii console, finding "highly compressed" versions is a top priority to save space. Here is how to handle compression effectively and safely. The Best Way to Compress Your Own ISO sengoku basara 3 utage wii iso highly compressed