This project is driven by omissions at the intersection of ecological game studies and media-ecology. Although authors have studied videogames from a variety of ecological approaches, few have attempted to develop a holistic methodology, embracing videogames' specific attributes while recognising their role within larger physical systems. This thesis is an attempt to address this, reading videogames as simultaneously about and functioning as ecologies. My methodology draws on the agential-realist philosophy of Karen Barad whose theory of 'intra-activity' is abundant with ecological ramifications. Adapting Barad's 'intra-active' framework for use with contemporary videogames, I read them as assemblages of hardware, software and their human players. I explore three significant aspects of game studies: interaction, aesthetics and affect. Focusing on interaction, I analyse the game Shelter.Emphasising the role of hardware and software, I read these processes in conjunction with an understanding of gameplay. This encourages a shift away from seeing gameplay as 'interaction' as it is defined within human-computer-interaction, and instead promotes a view that is 'intra-active'. Siding with Barad, play is radically reframed as a phenomenon that produces the apparent objects of its inception. In the second study I approach a series of more experimental games illustrating how an agential-realist worldview influences aesthetics. Analysing high-concept puzzle games Superhot,Antichamber,and Manifold Garden,I suggest that these games place a focus on aspects of ecology often over-shadowed in so-called 'natural' imaginings of our world, such as time, space and their entanglement. Finally, bringing my focus to the role of the player in my ecological understanding of games I analyse a number of short, human-centred or biographical games. Seeing the role of the player in an ecological manner, designers deviate from traditional methods of generating pathos and affect. Rather than developing empathetic relationships between player and avatar through immersion, viewing the player as only a part of an ecological system demands a posthuman response from players. These designers ask players to empathise while acknowledging their role is small and not central. This thesis presents a novel point of view that draws attention to the ambitious design practices of artists while suggesting new avenues in the future.