Tackling climate change demands behavioural shifts. Yet, individuals often face psychological barriers that hinder their engagement in pro-environmental behaviour. People struggle to vividly imagine how their actions are linked to environmental consequences and influence collective action dynamics. We designed a mobile video game intervention to promote sustainable food consumption by simulating choice-consequence scenarios within a fictional narrative. In our online experiment with UK adults, participants were randomly assigned to one of four game versions: Nature, which provides feedback through visual changes in the in-game environment; Social, which offers feedback through social interactions; Social+Nature, which combines both types of feedback; and a Control without feedback. We evaluate whether experiencing feedback in the video game interventions enhances real-world knowledge, attitudes, and behaviour as measured through an incentive-compatible grocery shopping task. We also evaluate the persistence of the effects 3 weeks after the interventions have been delivered. Participants treated three weeks prior maintained greater knowledge, stronger meat reduction intentions, and made more sustainable product choices.