I'll post an image from our concept art that was not really intended to go public, but it should answer your question. The planet does have a rather severe tilt to it's axis, though it is shown as straight up and down in this image. Please note the angle of the axis compared to the sun's location in the image. There are glacial fingers that extend out of the darkness and receive some sunlight as the planet rotates. However, these are quite limited.
