I haven’t played Qube, but from what I see from the images, this wouldn’t really qualify. Having no textures is not the same as having lo-res textures.
And even the very few textures that they use, are actually HD.
Those diagonal green lines would not be smooth if this was a lo-res texture.
Neither would these arrows be (at least from what I see from the screenshots they look nice and clean). If it was really lo-res they would look like Minecraft.
The difference between a hi-res and a lo-res texture on a high-poly model is the equivalent of wearing these two t-shirts:
Now think about having pixel art textures on ALL of things, including our skin, faces, buildings … All color information in the world would come in discreet, big pixels. That would be a lo-res texture, high-poly world.