Welcome to your interview.
The question is on your right: Choosing Abstract Classes vs Interfaces. Take a moment with it first.
Talk your thinking through with me if you like - when you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes). Discussion and graded submissions share your five interviewer interactions, so spend them well.
What are abstract classes and interfaces, and when would you choose one over the other in a game framework?