Some photos from Japan. :)
Legends say that people are still waiting for Android M for the ZF2.
I don't know if this is an appropriate reply but I have both Drastic (NDS emulator) and PPSSPP (Sony PSP emulator) on my Zenfone 2. Both run smooth as butter, on every game I have played on it so far, even the graphics intensive ones.
Don't blame the phone. Mine sleeps like a baby (1-1.5% per hour) stock, unrooted. Your setup is the problem. I'm running Greenify, Opera Max, allow Autostart to only the apps I want AND most importantly denying data access and keep awake to non-es...
Quick charge is so destroying your battery that i don't think it is so important...
Ah yeah, and smartphones emit enough radiation to mutate your DNA, right?