This paper reports the experiences in the design and execution of an object-oriented programming (OOP) laboratory course. In this course, the students are required to implement a small-to-medium scale interactive computer game in one semester, making use of a game framework. The students begin with a small number of the most tangible objects of an immediate concern. Then, as the semester unfolds and the game becomes increasingly sophisticated, OOP principles and design patterns are introduced as the means to cope with design complexity. The experience has indicated that framework-assisted, computer-game programming is a highly effective way to keep the learners engaged and facilitated in broadening and deepening their OOP skills. The ability to design nontrivial computer games that actually work has induced a consistently high level of sense of achievement among the students.