Aesthetics is an important aspect of the user experience. It is also among the principles for persuasive systems in the frameworks such as the functional triad by Fogg and the Persuasive Systems Design by Oinas-Kukkonen and Harjumaa. Yet, literature directly investigating the influence of aesthetics on persuasion is limited. Similarly, despite the significance of aversive stimuli on behaviour change, the research is also sparse. To understand how aesthetics affect reported persuasion, I designed a mobile app named Couch with two levels of each aesthetics and persuasion, utilizing aversive stimuli, with the aim of reducing sedentary behaviour. Participants reported significantly higher levels of persuasion in persuasive group compared to control group, showing the success of persuasion attempts. However, aesthetics had no significant effect on persuasion. I report additional findings regarding aesthetics, and discuss the implications for future work.