Existing Virtual World (VW) based curriculum oriented educational systems use conventional non-player characters (NPCs) to interact with users (players), represented as avatars, to guide and help them to accomplish learning activities. Also, few of them use some kind of gamification and keep data for user interactions and activities. In this paper, we present the design and implementation of an educational system based on VW technology, which employs gamification features, two types of NPCs, a conventional and an LLM based, and a Database that stores, apart from educational information, information about interactions of users with the NPCs. Evaluation of the system shows that both types of NPCs are useful for different reasons. LLM based ones offer more interesting dialogues, and conventional ones more targeted help.