@ Max King of the Wild
Development generally starts at concept and cost a pittance (at that stage and in comparison to later stages), this can be done well before any coding and take anywhere from weeks to months.
KZ2 began development before E3 2005, though the number of staffs involved in the project at the time may be nowhere near the current GG capacity. I would say a 4 years cycle for this game is more than reasonable.








