i can see throught the walls!?

here’s a photo36962-untitled.jpg

before i was experimenting with the editors i was clicking something. and when i came to the game the walls became slightly invisible you can see. before this the weren’t like this.

You most likely changed the alpha value of these sprites in the hierarchy panel, click on the wall/building and verify that the value “A” (alpha) of the color is 255 (if it’s lesser then the sprite will have transparency)