From playful design methods to artifacts that facilitate experiences of play, playfulness has been widely explored in HCI. However, this heterogeneous field of research lacks common ground – from a methodological, theoretical, as well as design perspective – which in turn creates problems that hinder related research outcomes. Towards common ground on playfulness, we propose these five lenses for reviewing, synthesizing, and critically engaging with literature: area of implementation, targeted audience, type of contribution, methodology, and motivation. To spark a discussion around the lenses, we probe them on a pilot review of CHI Play literature and discuss their relevance to future literature reviews that work towards making sense of the state of playfulness in HCI.