Is it difficult to organise the Generation Games?

No, it is not very difficult. The creative framework is available, including ready-to-use designs in the toolkit. You need enthusiastic organisers. Every community is capable of organising an edition, even without professionals. Teamwork will be important, connecting/involving expertise in the field of event management, communication, and so forth. Many hands make light work. Preparing the event is part of the fun. And you decide on the scale and ambition.