Unfortunately, the game was not able to be played. I launched the .exe, and I did not see any flappy bird or hear any SFX. I did see the cacti moving across the screen and they looked pretty good.
The pixel art I was able to see was nice looking. To make your pixel art look sharper in Unity, click on the imported sprite and set the filter mode to Point instead of Bilinear or Trilinear in the Inspector. Hope that helps!