This build features the unique weapon-overload system. You can still pick up two of the same weapon (Spread, Homing, Laser, etc.) to "Overload" it for a temporary screen-clearing super attack. This was not bugged in 13626439, unlike the day-one patch which had infinite overload glitches.
Repacks are a known vector for malware. However, Build 13626439 from trusted scene groups (Redump, SafeRepacks) has a clean track record. Always: Contra Operation Galuga Build 13626439-Repack
Navigate to: \ContraOG\Binaries\Win64\
Open Engine.ini and add: This build features the unique weapon-overload system
[/Script/Engine.RendererSettings]
r.ShadowQuality=0
r.VolumetricFog=0
r.PostProcessAAQuality=2
This boosts FPS by 15% on integrated graphics. Navigate to: \ContraOG\Binaries\Win64\ Open Engine