Well, honestly it was mostly from previous experience with programming, making mods, and making small games for game jams! But also it required tons of play-testing and over 10,000 lines of scripting! :O
impressive, is there some sorta solid statemachine (orwhatever its called) what people usually use for custom reload animations or npcs and items n shit -that you used to give maps the option of entering and re-entering from multiple points?