The trouble is that you really need to be a gamer to "get" the larger part of Space Funeral. Then again it's not like any other medium claims to be open to everyone: many are quite proud of their elitism. Perhaps this is what ticks so many people off about "art games": they are an attempt to be a sort of art that non-gamers can appreciate, and this generally involves butchering all their game-y elements (eg - "The Path"). Alternatively the "art" stuff is tacked on at the end: snippets of text or cut-scenes, but either way completely separate from the game itself (eg - "Braid", "Company of Myself", etc). I suppose I'm still waiting to see something that is artistic simply through its gameplay.
Not that this is an elusive "Holy Grail" or anything: your own game, Snakes of Avalon, requires the player to think illogically to solve puzzles, which puts them in the shoes of the protagonist more effectively than watching them as an outside observer would. It's little things like that that I like, but whether it's art is really up to the elitists: we just have to wait for the older ones to die off.
On a side note, I made a game that was all about the Hippocratic Oath, Justice, Sacrifice and Collateral Damage, all of which were woven into its mechanics. But nobody played it because, as a game, it kind of sucked