Lots of great feedback and suggestions. The enemies technically do spawn in lanes as they spawn on integers ranging from -3 to +4 on the z axis. To help I could make the lanes be more distinct, some kind of visual on the ground. Another possibility would be to give an alternate camera angle that is top down. Another option is that though the enemies spawn in lanes, the player can freely move. So I could constrain the player movements to stop at the center of a lane. Of the three, which would you like to see?
As for the town seeming more alive I was considering having there be frames and foundations before the house goes up but it would result in a lot more work for something that is scrolled passed in a few seconds. I'll see what assets are available on the Unity store.