This article describes the collection and analysis of a Swedish database of spontaneous and unconstrained children-machine dialogues. The Swedish NICE corpus consists of spoken dialogues between children aged 8 to 15 and embodied fairytale characters in a computer game scenario. Compared to previously collected corpora of children's computer-directed speech, the Swedish NICE corpus contains extended interactions, including three-party conversation, in which the young users used spoken dialogue as the primary means of progression in the game.