If you're looking for scary games, Song of Horror was one of the more unnerving ones for me.
ExtraMedicated
(On my wishlist for years)
Well now I don't feel like playing it.
La-Mulana would have to be one of my top picks. With the catchy music, the "fuck you" difficulty, and the classic adventure theme really makes it stand out in my mind.
It looks like there are a few games I was slightly interested in trying at some point, but not enough to buy them, but having so many together as a single purchase, I couldn't resist. I even paid the default price of $20 instead of $10.
Shadow of the Collossus
I don't remember if it was on sale, but I got 10 Dead Doves on a whim and I'm not dissapointed so far.
Run for office and be the lesser evil.
I wouldn't say no to another Echo Night.
I didn't migrate yet because I was five years into a project that I can only work on in my spare time, but you can bet that if I ever start another game, I'm looking at a different engine.
I think this is the only thread where I actually haven't seen any of the games before.
Another game I enjoyed was The Eternal Castle (remastered). It's a remake of a game from 1987. The animation is great and the visual style is really cool.
I haven't played this yet, so I don't know anything about what difficulty settings it may or may not have But in general, I see difficulty settings as an accessibility feature.
I liked the way that Ender Magnolia did it, where, at a save point, you could adjust several settings to customize the difficulty. I was able to temporarily make it slightly easier just for a few bosses that I lost my patience for.