Managed to compile xgalaga-sdl. It is working well with the zynergy ROM. Took a little while as the image loading routines use Xpm. Hence I had to compile the X11 libs. It does not require an xserver as sdl is used for display and audio.
Strangely though, even though I set its height to 320 and width to 240, it only runs when qtopia is in landscape mode (which makes the game run in the intended portrait mode!) and with the left and right keys reversed. Edited main.c to reverse the keys and it works. But this is just a hack.
Anybody have any idea what is going on here?