YogSo: This list is shaping up nicely. I can't really help with
PixelJunk Eden, because I've not tried it, but if it plays just like any other platformer I wouldn't include it here. From your original post:
"The aim is collect the games which goes into the category "alternative","art" games, "is it really a game" and so on." I don't think just having an 'artsy' art-style is enough. Otherwise, there would be lots of indie games (especially platformers) that should have to be included, when the only 'alternative' quality they have is an unusual art-style. Or things like
Zeno Clash, which has a delightfully weird art-style, but at its core is 'just' a first person brawler (and occasionally, shooter). All this in my not-so-humble opinion, of course. :-)
This reminds me, though, I've been thinking about
Sword & Sworcery EP. I've just played the first 2 acts, because the game hasn't really grabbed me so far, although I plan to return to it to complete it at some point. It has a lot of those hard to explain 'artsy' qualities... but I'm not sure the gameplay is experimental enough to set it apart from other platformers. What do you think?
Ah, and finally, another game that I think deserves to be in this list without a doubt:
Ruins (Exploration, Narrative).
mm, it is for the same reasons S&S is not there - the list is not to be of indie games, but for experimental titles generally. Proun was another that I kept debating with myself if it really tries to experiment with the media, and I did in the end put it up there as I felt it did, but at a level it is just another racer based on the old Star Wars formula.
Thanks for Ruins, by the way, another one I forgot about.