I honestly can't remember where I first saw it - I actually played this back in February or so and just got around to putting this up! IndyGamer seemed like a reasonable guess. I think I must have actually seen it on IndieGames, here: http://www.indiegames.com/blog/2010/01/freeware_game_pick_the_mccarth.html

And I've got to say I loved the Chzo games :) As odd and ill-advised as some of their gameplay was, the story really picked up as the series went on, and I've got to have respect for games that scared me that much.