This article discusses methodological considerations of user-centred design for non-human animals. These considerations are illustrated through a design research project that aims to apply digital technology to build games for orangutans’ enrichment. The article argues that design for other species reveals limitations of designers’ knowledge of prospected users. The article explores how to approach participants who cannot express themselves verbally and how to recognise play that may not look familiar to the designer. The article finally presents a participatory design method that allows for non-human contributions in design. This method applies play as an interspecies co-creative act and can be used as a starting point for addressing questions of difference in play and designing games that allow for ambiguous play.