Granted, these games aren't everyone's cup of tea, but if it works for you and you want more, there's a whole art-games movement and lots more around (though I think Jason Rohrer is among the better known designers). Many of the games are free for download or playable online.

Good places to get started are:
PlayThisThing.com -- a game review site that covers game design and out of the mainstream games, including art games (search for "art" and you'll mostly get what you're looking for).
Jason Rohrer's web page, which includes downloadable copies of most of his work --
http://hcsoftware.sourceforge.net/jason-rohrer/
and blog (not updated in over two years, but there is still good content on older art-games there):
http://www.northcountrynotes.org/jason-rohrer/arthouseGames/

These pages also have some nice links and write-ups on art-games:
http://www.artificial.dk/articles/artgamesnetworks.htm
http://www.56kmodern.com/

Since many designers of art games work on their own, the Indie Games community is also a good place to look for stuff that's a little unusual:
http://www.igf.com/
http://www.indiecade.com/

Chris