The image in the back is an HDR image, which is essentially an image sphere that will give the material i used some color to reflect, which reduces the effect of "black light" (basically the same effect as looking at a mirror in a dark room).
As for the game over screen, I downloaded some brush tools to use in Photoshop and used basic text on a black background. Not exactly the best game over screen in the world, but that can always be changed later if we decide to change it.
I feel like I should have used the splatter effects behind the words "Game Over" instead of in front of it, and I feel like there is also too much negative space in the back as well. I'll find out what to do with that later.