You can't turn it off in older versions of Windows 10 ( you can but it requires a registry edit)
Oct 2018 edition you can.
That said, game mode isn't as important, Game DVR is the most important one to turn off.
You want your log to look like this
16:55:48.136: CPU Name: AMD Ryzen 7 2700X Eight-Core Processor
16:55:48.136: CPU Speed: 3693MHz
16:55:48.136: Physical Cores: 8, Logical Cores: 16
16:55:48.137: Physical Memory: 16310MB Total, 10634MB Free
16:55:48.137: Windows Version: 10.0 Build 17763 (revision: 134; 64-bit)
16:55:48.137: Running as administrator: true
16:55:48.137: Aero is Enabled (Aero is always on for windows 8 and above)
16:55:48.137: Windows 10 Gaming Features:
16:55:48.137: Game Bar: Off
16:55:48.137: Game DVR: Off
16:55:48.137: Game DVR Background Recording: Off
16:55:48.138: Sec. Software Status:
16:55:48.139: Windows Defender Antivirus: enabled (AV)
16:55:48.139: Windows Firewall: enabled (FW)
16:55:48.139: Windows Defender Antivirus: enabled (ASW)
16:55:48.139: Browser Hardware Acceleration: false
16:55:48.139: Portable mode: false
16:55:48.235: OBS 22.0.2 (64-bit, windows)