Some general thoughts.
I assume your target audience will know the game from the thumbnail? If not some detail as to what game this is would be useful.
The elements in the corners will be very small. Have you checked them at the size most people will see them at (e.g. YouTube search results, channel video list, etc.) to see if they are legible?
From a design perspective, it is good to leave a "gutter" around the image. So bring your text up from flush with the bottom and bring your avatar our from the corner. More like how you placed the oculus icon.
Outside of that, it will be a matter of watching your CTR and comparing it to your other thumbnails.