[Intel] The Microsoft Game API (GAPI) is a lightweight API aimed at high performance gaming and visualization applications. With only twelve functions in the entire API, GAPI doesn’t attempt to be DirectX on the Pocket PC platform. As an API designed for an embedded system, GAPI strives to provide the most efficient access to the underlying input and graphics hardware without impacting overall performance.

Nice article about GAPI on the Compact Framework for both Pocket PC and Smartphone 2003.