“COLUMNAE: A Past Under Construction” is a non-linear point & click adventure game set in a post-apocalyptic steampunk world and developed by Belgrade-based Moonburnt Studio. Aside from the classic point & click adventure features, COLUMNAE introduces the concept of retrocausality which along with non-linear nature of the gameplay allows the player to affect not only the future but also the past of the main character and the world surrounding him. The game is divided into eight chapters, but the order of playing them is not chronological. Depending on the actions the player chooses within each chapter of the game, yet-to-be-played chapters are placed in an appropriate “version” of the past or the future.