This chapter discusses the possibilities and limitations of critical war game development. Paraphrasing Mary Flanagan (2009), by a 'critical war game' we mean a game that through its procedural rhetoric and/or narrative frames challenges the established design practices and generic conventions that dominate the representation of war in video games, and potentially innovates.This chapter stems from our experience of developing the game Attentat 1942 and summarizes key lessons learned during the process.As such, this chapter could be of interest to other critical and/or serious game developers, as well as researchers in game studies and cultural studies alike.