This paper presents a qualitative study of a school-university collaborative project where a game-themed CS1 course was offered as-is to high school students. Our specific interest was to explore the students' experiences with the university level course. Our analyses indicate that immediate and regular support was highly important for student performance, as support of this kind could mitigate issues related to students' orientation towards the high workload of the course. Students who showed academic interest were likely to pass, whereas students lacking self-direction or work efficiency were likely to drop out. Both passed and drop-outs found the course to be a good learning experience. The game theme of the course was in most cases found highly motivating and fun, while it was not a necessity for the majority of the students. This information can be utilized by higher education instructors who plan to carry out university courses in cooperation with high schools.