I like this paper. I like it not only because it reaffirms the (sometimes controversial) principle of fun in learning, but also because it explores what fun means, and does so by creating a fun activity. In short, it's fun. This wider conception of fun is in accord with Seymour Papert's ‘hard fun’ and James Paul Gee’s ‘regime of confidence’ (sometimes stylized as 'flow'). It's the fun I experience when coding a Tic Tac Toe game. But the authors also note that "studies in this area are limited by a tendency of both researchers and participants to investigate, report,and emphasise only socially acceptable views of fun and its relationship to learning." Hence, say, the term 'serious games'. Blech. I think we should embrace fun in all its flavours.