This paper presents a game-based approach for raising young children's online risk awareness, to decrease the risk of becoming the subject of sexual grooming. Hidden in the Park is an adventure game, including a classic game board and a tablet with Augmented Reality-technology. The game mechanics are based on data from true grooming processes. The game's target group is children aged 8-10 years. This paper describes the game development, from a prototype to an approved release version that will be released as a non-profit product during 2019. We describe the creation of the game mechanics, the iterative development process, and game evaluation. 25 pupils in the target group participated, but the ages 7-12 (n=70) were included to evaluate whether the game would suit the intended target group. Results show that the game is fun and engaging but that it also raise questions concerning online activities.