To increase engagement, various tools and methods have been introduced in education, including gamification and game-based learning (GBL), both in analogue and digital form. Gamification involves adding elements of game design to existing learning scenarios to increase extrinsic motivation, while GBL involves developing games specifically for achieving learning objectives to promote intrinsic motivation. Examples of educational games in chemistry include virtual labs, nomenclature games/puzzles, quizzes on chemical properties and the exploration/construction of molecular structures. Serious games are a type of GBL for the development of specific skills that often involve experiential learning, e.g. simulations. In chemistry education they not only promote active learning but also provide a safe environment for conducting experiments.

The aim of our study was to review research on the use of games and gamification in chemistry education in order to identify trends and new research opportunities. Data were retrieved from the Scopus database, where titles, abstracts and keywords were searched for a combination of synonyms related to games/gamification, education and chemistry, and we limited the results to journal articles (including reviews) and conference papers. After screening for false positives and duplicates (approx. 60%), 591 documents remained. Microsoft Excel, Bibliometrix/Biblioshiny and VOSviewer were then used for the bibliometric analyses:
1) performance analysis (tables/charts) – annual production and citations, most cited documents and references, most prolific/cited authors, countries and sources;
2) science mapping (network diagrams) – co-word analysis on titles and abstracts, co-authorship analysis of authors and countries.

The results show that publication began in 1976 and has increased rapidly over the last 10 years. By far the most papers on games in chemistry education were published in the Journal of Chemical Education, which is also the most frequently cited. The most cited articles deal with escape games, virtual reality, and gamification. The most cited references focus on escape games, game design and card games. Da Silva from the Federal University of Ceara in Brazil is the most prolific author with 19 contributions and also received the most citations. The USA is the most productive country with 20% of the papers, while United Kingdom was the most collaborative country. Combined terms from titles and abstracts were analysed to identify the most important research areas.

Five clusters emerged, categorised by game and research type:
1) serious games (video, simulations, virtual/augmented reality) with case studies,
2) digital games with empirical studies,
3) escape games, puzzles and game design with active learning,
4) card games and quizzes with usability studies,
5) didactic games with observation and inquiry,

The newest terms used included chemical bonding, escape room/game, active learning and pandemic. Quiz, academic performance and smartphone were also high on the list. The most cited words in the titles and abstracts in relative terms were experimental group, game design, chemical bonding, effort and enjoyment.

This study provides an overview of the field and is a valuable guide for researchers and teachers to find relevant literature and journals in which to publish. Topic structure, developments over time and citation data help to identify trends and research gaps that could be filled.

Keywords: Gamification, game-based learning, chemistry education, bibliometric analysis.