BrainForm: a Serious Game for BCI Training and Data Collection

$\textit{BrainForm}$ is a gamified Brain-Computer Interface (BCI) training system designed for scalable data collection using consumer hardware and a minimal setup. We investigated (1) how users develop BCI control skills across repeated sessions and (2) perceptual and performance effects of two visual stimulation textures. Game Experience Questionnaire (GEQ) scores for Flow, Positive Affect, Competence and Challenge were strongly positive, indicating sustained engagement. A within-subject study with multiple runs, two task complexities, and post-session questionnaires revealed no significant performance differences between textures but increased ocular irritation over time. Online metrics$\unicode{x2013}$Task Accuracy, Task Time, and Information Transfer Rate$\unicode{x2013}$improved across sessions, confirming learning effects for symbol spelling, even under pressure conditions. Our results highlight the potential of $\textit{BrainForm}$ as a scalable, user-friendly BCI research tool and offer guidance for sustained engagement and reduced training fatigue.