Is it possible to help to play my scene more quickly, I mean how to decrease the resolution during the output playing!?
Decreasing the resolution isn’t usually the best way to help with performance, since it will result in blurry graphics. You can disable Device Pixel Ratio (found in your project Render Settings) to help with mobile or high pixel density displays.
Also take a look at this manual page and also the following thread for more info on performance optimizations: