No, being too eager and interested during a college interview is not bad. In fact, it can be beneficial to demonstrate your enthusiasm for the school and show that you are passionate about attending.
Having an eager attitude will make you stand out from other applicants who may seem less engaged in their interviews.
However, if taken too far it could come across as unprofessional or desperate which would likely have a negative impact on how admissions officers view your application overall.
It's important to strike a balance between showing genuine interest and also appearing confident in yourself without coming off as overly enthusiastic or pushy about wanting admission into the program/university.
Taking time before the interview to research what makes this particular school unique and why it appeals most to you is recommended so that when asked questions concerning these topics, you're able to provide thoughtful answers while still demonstrating excitement at having been selected for an opportunity like this one.