There are two ways of playing a video from Google Drive:
The easiest way is through the browser, but the client will also provide ways to manage your files more easily than the web version.
To play a video, install Google Drive, then sync your entire cloud to PC or choose only the folder with the videos. Wait for Google Drive to synchronize the files and then browse its folder on your computer. After this, load the file in your favorite video player to watch it.