The massive presence of plastic in the oceans, both in form of large debris and micro-plastic, is raising global concern due to its serious effects on the marine environment and fauna, causing loss of biodiversity and potentially threatening human health. Even though this is due to poor waste management, the great production and consumption of single-use plastic is a significant exacerbating factor. Despite policies and bans can be effective measures, there is also the need to raise consumers' awareness, so they can make more sustainable choices when purchasing, using and, dismissing products. In particular, educating young citizens and encouraging them to engage in pro-environmental behaviors is a fundamental task to reach this goal. In this work, we present Contact from the future, a digital game on plastic pollution for children, to create awareness and stimulate pro-environmental behaviors, discussing the definition of objectives and requirements, as well as the design and development of the application.