It took quite a bit of finagling, but the devs over at Drunken Coders have finally ported Quake II to the Nintendo DS. The homebrewed version contains the entire single-player game, and retains a number of fancy features like dynamic lighting, particle support, and a full ARM7 sound effects system.
According to the devs, creating Quake2DS was quite the audacious task, as the original Quake II had memory requirements that far exceeded the DS's limitations. As a result, the port will only run on flash carts with RAM expansions. Those willing to give it a go will find relevant instructions and files on the port's website.