These two creations by Nick Trotta (tardisblue) were part of the Space Vikings display at BrickCon 2014.
Skjoldr defense cannon:
The cannon has a gear-operated locking mechanism to control its angle- fantastic! I also really like its triangular barrels and the use of ladder elements for that "grille" texture. The ship, too, makes good use of alternating smooth and blocky textures and interesting shapes.
See the whole Space Vikings collaboration on Flickr here.