The idea of architecture entrenched in physical descriptions is traditionally what is espoused in the practice of architecture in academia and the application of such ideas are attended to in practice, but the greatest benefit in relation to architecture that level designers have is their ability to escape from reality which affords them a far less limited description. There are still rules in constructing a level, but a level designer need not pay attention to rules which prevent them from designing constructive things in the real world. There is no need to pay attention to physics or restrict the mode of design to the set of methods possible in the real world. Therefore we need a more abstract conceptualization of what architecture is that is useful to level designers. A more useful definition is that architecture is the visuospatial characterization of geometric details over base geometry, which is collectively the most basic forms of geometry needed to visualize location.
Despite level design being an escape from reality the machines that interact with the level are still human, and so the rules of being human still apply, which is why adopting the exploitation of phenomena discovered in neuroscience is appropriate. Intuitively architecture in this more abstract definition performs two interrelated purposes: telling the same story and doing so in a different way. It’s highly unlikely that a level designer will be able to build a novel template on which architectural detail can be added since there are not many different ways to lay out the foundational geometry that have not already been done before. One might even claim they have discovered a new template only to discover that it can easily be characterized and traced back to something that has already been seen. A church is the perfect example. The template is the same, the details are different. So structure in architecture should optimize the visuospatial characteristics of the template for the sake of evoking a desired response in the viewer as structural detail contributes to the phenomenon. So the difficult question that arises is “What makes better structure?” Paying attention to what visual stimuli are more capable of invoking a particular response or mood on the part of the viewer allows us to determine that architecture which is more influential in provoking a response along with visuals that coincide with a human notion of aestheticism is structurally better than architecture that is less influential in doing so. This doesn’t mean that architecture can’t be “ugly” in the sense that a level designer might want to invoke a dark mood or a sense of disgust, but rather architecture that is less able to do so and is aesthetically nonsensical is purely inferior to architecture that is not. In every case looking at the concepts behind the details give an intuition of what the human brain feels in most cases. Humans group objects based on visual characteristics like shape, color, and spatial distance . Architecture can then be analyzed in a hierarchical way, in which structures contain substructures and the quality of those substructures combined with the quality of the larger structures provide a sense of quality of the whole visual construct. Those structures are the visual things humans group together. Two key principles to pay attention to are the orientation of symmetry and the harmony of ordered wholes. There are various kinds of symmetry but structure has to maintain symmetry somehow for the maintenance of proper structure, given that the human brain pays an elevated level of attention to symmetry . The latter is something which I am in the process of figuring out, but it doesn’t seem to be the same thing as symmetry. The best description I can give to it is the geometric respect for natural order. You can find plenty of ugly buildings in the world but I have never seen a building which was built in a way which violates this principle, perhaps because it is in the very nature of humans to avoid it innately. There is a visual orderliness in the universe in anything which by its nature has structure. This may need not apply, therefore, to fluid, for example. A great violation of this principle may be imagined. Take a look at the Forbidden City.
Now, in your mind, for every set of n fixed units in a cubic region, take any geometry that exists within that region and rearrange it in any arbitrary manner, through rotation, extrusion, decimation, scaling, stretching, splitting, et cetera in a manner totally different from every other region you have modified. This would be an ideal opposite of harmonious ordered wholes, which may perhaps simply be related to chaos in a geometric sense. The whole point of structure is the maintenance of visual order and in architecture it is done hierarchically. Since we have an idea of what not to do we have a sense of what to run away from and how to do it, which at least gives us an intuition of how to qualify structure.
Within a foundational structure creativity can be realized in how the designer applied innovation to what has already been done and how they manipulated the visual template in order to creatively maintain its structure yet give it a unique personality. Tōdai-ji is in a geometric sense built upon the same template as the Forbidden City, yet the two have architectural details which contrast them so much that they are uniquely distinct from one another.
Having covered how to roughly qualify architecture in level design we can focus on the specific ways in which the human mind can be influenced by the spatial and visual structure of architecture. Symmetry, for instance, can be used to highlight differences and similarities. A focal point in a symmetrical space can be used to orient the viewer in order to aid them in absorbing a scene wholly. Repetition of visual motifs allows simultaneous processing of the visual figures being repeated. There is also some work that may suggest that facades themselves influence mood, and perhaps if a relevant portion of the cortex that is stimulated is the same portion which is involved in the processing of human faces, there may even be a more grounded sense of what distinguishes aesthetic facades from unaesthetic ones. Some work has been done attempting to use machine learning for face recognition (SVM) in order to extract from facades those inputs that would otherwise be recognized in faces and assign to them particular moods , albeit this may not truly relate the data to the phenomenon through which processing faces occurs in the human brain the phenomenon of pareidolia has been studied for some time.
So it’s evident that architecture is a profoundly relevant factor in level design and can be used to further the very purpose of level design as an interactive art.
 “Gestalt Principles”. Web. http://graphicdesign.spokanefalls.edu/tutorials/process/gestaltprinciples/gestaltprinc.htm
 Symmetry activates extrastriate visual cortex in human and nonhuman primates. Yuka Sasaki, Wim Vanduffel, Tamara Knutsen, Christopher Tyler, Roger Tootell. Proceedings of the National Academy of Sciences Feb 2005, 102 (8) 3159-3163; DOI: 10.1073/pnas.0500319102
 Simulating Paredolia of Faces for Architectural Image Analysis. Chalup, Stephen K., Hong, Kenny. ostwald, Michael J. International Journal of Computer Information Systems and Industrial Management Applications (IJCISIM) Vol.2 (2010), pp.262-278