I'm not even interested in these games but I went ahead and ordered a bundle for $8.50 just because I'm a huge fan of pay-what-you-want concepts and the Humble Bundle execution of this concept is awesome.
If you haven't played them, do yourself a favour and try them, they are all very good games and well worth their original prices.
I don't consider myself a huge wuss but I'm still only about half way through Amnesia -- make sure you play late at night with the lights off and good headphones on.