xgalaga for windows
Here is a little hack of xgalaga sources. This version is based on xgalaga-2.0.34 by Joe Rumsey and others (see original README in source distribution for details)
You get here windowed mode or fullscreen and sounds. I did the code quite on a rush so it is not really clean. Main issue was to separate graphic code from ai code. Still have to improve this one day or another !!!
I guess this piece of code is under GPL.
Enjoy

Note about building in msdev
Add . as include path for #include
#define SOUND
Link with winmm.lib, ws2_32.lib, ddraw.lib, dsound.lib
Run from top directory, where you see sprites.bmp, /levels, /sounds

Download exe file xgalaga-2.0.34-w32bin.rar
Download source files xgalaga-2.0.34-w32src.rar