Commercial brain games are home-and computerbased cognitive trainings that are industrially offered and promise to enhance cognitive functioning by repeating cognitive tasks. Despite compelling evidence for the effectiveness of cognitive trainings in various domains and populations, the assumption of brain games' effects on people's minds has been challenged. However, there are only very few attempts to systematically evaluate the effectiveness of such games under ecologically valid training conditions. To approach this gap in the literature, we applied commercially available training tasks assumed to tap into working memory updating and capacity. The effectiveness of this training was measured by utilizing pre-and post-tests in trained tasks (criterion tasks), untrained transfer tasks from the assumed training domains (near-transfer tasks), as well as from the domains processing speed, shifting, inhibition, reasoning, and self-reported cognitive failures (far-transfer tasks). Training as well as pre-posttests were completely administered home-based. In contrast to an active control group, a training group improved performance in the criterion tasks and near-transfer tasks. Improved performance was also evident in processing speed and shifting tasks (i.e., far-transfer tasks), but these improvements were not as conclusive as those in near-transfer tasks. Further, the number of reported cognitive failures was reduced in the training in contrast to the control group at post-test. Performance improvements were more pronounced for highperforming participants (i.e., magnification effects). In general, this study provides an evaluation of the effectiveness of a particular set of working-memory training tasks in an ecologically valid setting in the context of brain games.