Refreshing to have a game that is not time-based. I also think you're not giving yourself enough credit by saying the visuals are just the shader you downloaded. There's a lot of tweaking and color work there that make it come together to a very cohesive image.
However, at a mechanical level, a lot of plays feel forced. I assume the game opens up when you get more perks, but it could also be a little more complex in the early game. It feels like its missing some core system to pull it together.