Gaming will always have am affect on the battery on the device. Have you tried letting the battery reset itself by letting it drain to 0% and then charging it back up to 100% before use?
Sent from my Nexus 7 using Tapatalk 4
Samsung Galaxy S3 (SGH-i747) | Android KitKat 4.4.2 CyanogenMod 11 Nightlies
Samsung Galaxy Tab 2 (SGH-i497) | Android JellyBean 4.1.2 Stock
Nexus 7 (2013) | Android KitKat 4.4.2 Stock
Is my post helpful? It's always nice to hit that 'Thanks' button!