This paper describes the Generic Automated Marking Environment (GAME) and provides a detailed analysis of its performance in assessing student programming projects and exercises. GAME has been designed to automatically assess programming assignments written in a variety of languages based on the "structure" of the source code and the correctness of the program's output. Currently, the system is able to mark programs written in Java, C++ and the C language. To use the system, instructors are required to provide a simple "marking schema" for each given assessment item, which includes pertinent information such as the location of files and the model solution. In this research, GAME has been tested on a number of student programming exercises and assignments and its performance has been compared against that of a human marker. An in-depth statistical analysis of the comparison is presented, providing encouraging results and directions for employing GAME as a tool for teaching and learning.