Emotion is a huge factor in creating immersive experience when playing a video game. It can be stimulated by visual design elements. In particular, different levels of realism have an effect over the human feelings. Referred to as the Design Style, it is a spectrum of mimicking the real world ranging from Abstract to Realistic. Between them is known as Stylized Design. While there have been many studies to understand the relationship between Design Styles and emotions, their experimental observations lack quantitative analysis and prone to misinterpretation. Electroencephalogram (EEG) technologies have made the possibilities to explore emotional responses directly from the brain. This research aims to understand the relationship between Design Styles and the emotional responses of the player. To analyse design styles for correlation with emotions, a working framework for machine learning classification using EEG is used. Subjects played video games of similar gameplay but of two different Design Styles – each game represents each end of the Design Styles spectrum. Analysis of the EEG data revealed distinction of emotional activity between Abstract and Realistic games. Higher intensity, larger data distribution, and abruptness of change in emotions are all associated with Abstract Design. Realism, on the other hand, is associated with a more sustained emotional state and therefore a good choice for maintaining a steady mood.