I'm new to Unity2D,
So I'm creating a game in 2D where AI agent and enemies walks around a floor with doors to spawn the enemies and alcoves to hold the items that the agents has to collect. I created circles to represent the enemies and applied a material with red color on it. But in the game play, the color is black as you can see in the following picture:

Also, the two of the grey walls are missing as well in the game play. The floor has z-position = 0 and the obstacles has z position -2. 

[![enter image description here](https://i.stack.imgur.com/ktad3.gif)](https://i.stack.imgur.com/ktad3.gif)

Furthermore, I used `transform.Translate(new Vector3(movingSpeed,0,0) * Time.deltaTime);` in the fixedUpdate method to move the object, but in the game play it went off super fast. However, the movingSpeed is only set to 0.01. 

[![enter image description here](https://i.stack.imgur.com/zWDXE.png)](https://i.stack.imgur.com/zWDXE.png)