Companies nowadays use various business intelligence and analytics (BI&A) platforms to support decision making. Key challenges for users are to efficiently interact with BI&A platforms and quickly comprehend the insights. The research field that studies user-centric design of systems is Human-Computer Interaction (HCI). A lot of research has been conducted to define HCI principles and to design evaluation models in Information Systems (IS). However, BI&A platforms seem to differ from other IS due to information overload and massive data visualization. These factors are making the evaluation of HCI principles in BI&A platform more complex. In this research in progress paper, our goal is to study HCI in BI&A platforms. For this purpose, we redesigned the interface of a retail BI&A platform, maintaining the same amount of the displayed information. In a lab experiment, business users evaluated both versions according to three HCI elements i.e. usability, user experience and aesthetics. During the evaluation, we recorded their expressions, errors and runtime. Short interviews aided us in identifying which factors, associated with these three HCI elements, mostly affect the ability of users to effectively interact with the platform. Closing, we also studied what interface improvements impact the comprehension of the visualized information.