Underground Mars colony for 1000 people by InnSpace

A weak ago we posted a concept of Mars colony for 1000 people created by InnSpace team from Poland for Mars Colony Prize contest (held by The Mars Society). In some of the responses there was a critique stressing out the colony should be built underground for better radiation protection. Since then the authors of the concept sent us some additional renderings from which we can conclude it's actually the case - the concept includes most of the buildings being built underground (with only the transparent rooftops sticking out from regolith cover for natural lighting) and interconnected via underground passages.

A hyperloop line entering the colony:

Cover layers for underground passages between buildings: