Have you tried running GoW 2 on your phone? Let us know your settings in the comments below!
You cannot run a .7z file directly in an emulator. You must first extract it using a file extractor like ZArchiver on Android or 7-Zip on Windows. Extracting it will reveal the actual playable game file, usually in .ISO or .CSO format. Playing via PPSSPP GOD OF WAR 2 PPSSPP Zip -New Edition-.7z