Major usability and technical challenges have created mistrust of the potential of brain computer interfaces used to control video games in challenging environments like healthcare. Despite several studies showing low cost commercial headsets can read the brainwave patterns of its users with great potential for long term adoption; there are limited studies showing its efficacy in concrete healthcare scenarios. In our past work, we developed FarmerKeeper, a BCI using users’ attention to control a runner videogame to support neurofeedback therapies with great usability and user experience. In this paper, beyond usability, we describe the results of a 10-week deployment study with 26 children with severe autism using FarmerKeeper as a tool to support the neurofeedback therapies of children with autism. Pre- and post-assessment evaluation indicate all children with autism improve their attention, attentional control and sustained attention. Two children with autism no longer showed attention impairments in the post-assessment evaluation. We closed discussing directions for future work and the potential benefits of this new generation of BCI videogames in healthcare scenarios.