As social robots' and AI agents' roles are becoming more diverse, those machines increasingly function as sociable partners. This trend raises questions about whether social gaming gratifications known to emerge in human-human co-play may (not) also manifest in human-machine co-play. In the present study, we examined social outcomes of playing a videogame with a human partner as compared to an ostensible social robot or A.I (i.e., computer-controlled player) partner. Participants (N = 103) were randomly assigned to three experimental conditions in which they played a cooperative video game with either a human, embodied robot, or non-embodied AI. Results indicated that few statistically significant or meaningful differences existed between any of the partner types on perceived closeness with partner, relatedness need satisfaction, or entertainment outcomes. However, qualitative data suggested that human and robot partners were both seen as more sociable, while AI partners were seen as more functional.