Bridge Builder is a puzzle video game series, created by US-based indie developer Alex Austin. Bridge Builder being the first in the series, it was followed by four sequels in different versions, all of them developed and published by Chronic Logic, the only exception being Bridge Project, which was developed by Halycon Media and Caipirinha Games, some of the games also feature secondary publishers. The objective of each game is to construct a bridge which a train may cross over, given a limited budget and materials.