I have updated my Castle Defender with full NTSC support – complete recolor when NTSC detected, so the game now looks almost identical when running PAL or NTSC.
I have removed a glitch that caused lost vsync when switching from game to the menu on Victory or Defeat.
I have also moved the sources to github:
https://github.com/matosimi/CastleDefender

Download
On the main Castle Defender page.