We can start with the first level, it looks like the unreal base test scene, all the movements and camera are freezing.
About the city level everything is out of scale, all the foliage is without alpha transparency.
The character is totally from a different kind of scene, talking about the design, compared to the lowpoly houses and buildings.
It looks like you took few models packages and you placed everything there just to pull out a game without an idea.
P.S. I'm talking about what I've seen in the video you posted, I wanted to play it but it requires to be registered, I downloaded the game but I didn't feel like giving my email address to a stranger.