In 2012 the New Zealand Government identified as a priority the need to address the undersupply of students studying STEM subjects for delivering its Business Growth Agenda. Low engagement and retention rates in STEM subjects contribute to the shortage of STEM graduates, producing a negative impact on the New Zealand economy. This Teaching and Learning Research Initiative (TLRI) -funded project implemented and evaluated a pedagogical intervention aimed at enhancing learner engagement in STEM courses and increasing learners' creativity more generally. The primary aim of this project was the evaluation of a strategic and innovative pedagogical intervention based on Puzzle-Based Learning (PzBL) in undergraduate STEM courses. To fulfil this aim, the project sought to answer three important research questions: (1) Does the integration of non-routine problem-solving in lectures affect participants' engagement in lectures, and/or their ability to inhibit intuitive thinking and exhibit creative thinking?; (2) Are any observed effects moderated by individual differences such as demographic characteristics or prior ability?; and (3) How do students react to the integration of non-routine problem-solving in their lectures?