Research has explored escape rooms for their education potential but there is a notable lack of literature in the public engagement context. This paper illustrates findings from three editions of Back for the Future, a climate-themed STEM escape room delivered both online and in person, with and without COVID-19 restrictions. We demonstrate that escape rooms can engage those who normally do not seek out science in an enjoyable experience that may foster future engagement. Players become immersed in the game environment, losing track of time and can succeed in the activity regardless of their science background. We also propose that self-determination theory, science capital and flow are beneficial concepts for designing games that enhance engagement for a variety of audience groups. Finally, we hope to provide useful and generalisable recommendations for delivering impactful STEM escape rooms in unexpected places (and perhaps with unexpected limitations).