Index: src/game_config.cpp
--- src/game_config.cpp.orig
+++ src/game_config.cpp
@@ -86,7 +86,7 @@ void LoadConfigFile() {
 }
 
 void SetConfigDefaults() {
-	param.fullscreen = true;
+	param.fullscreen = false;
 	param.res_type = 0; // 0=auto / 1=800x600 / 2=1024x768 ...
 	param.perf_level = 3;	// detail level
 	param.language = std::string::npos; // If language is set to npos, ETR will try to load default system language
