While I move the camera, the pixels of the geometry are moving as well.
For perspective projection I use
glm::perspective( 45.0f, float( screenWidth ) / float( screenHeight ), 1.0f, 140.0f );
I draw the cubes per side.
This seems like an easy question. Should I set the resolution higher somewhere?
As Bartek Banachewicz commented, enabling Anti Aliasing in OpenGL fixed the issue.
I am using MSAA for Anti Aliasing.