SpaceFighter is a game that wants to model the complexity of time based competitive urban developments. It wants to reflect and compare imaginable forecasted, interactive urban processes, actions and reactions. It compares series of selected and possible projective simulations, results and outcomes of urbanistic chain reactions. SpaceFighter builds on the accumulated knowledge of MVRDV's Regionmaker and Climatizer. Yet where the Regionmaker was about scenario building and the comparison of scenarios, SpaceFighter wants to model the interactive process beyond scenario making. Scenarios are based on a given, limited set of outcomes, while interactive models can generate outcomes that never could have been imagined beforehand. One can imagine that as soon as a scenario has been laid out, reactions appear. And, as soon as these reactions have appeared, the planner is forced to interact in order to 'deal with these reactions', which results in a new interaction, which in its turn triggers new reactions, etc. SpaceFighter seeks to model interactive urban developments as an evolutionary process.