It's a very tricky tonal tightrope The Skeleton Twins wants to walk, and save a couple wee wobbles I'm pretty certain that from wher I was sitting it gives us gawkers a good and stylish show. First, the minor quibbles - you ladle it on with those skeleton dolls a little thick; we get it, we got it fifty minutes before that, maybe even when we walked in the door, heard the name of the movie, started breathing - we got it.
Also Bill Hader maybe refers to himself as the "gay" fill-in-the-blank (uncle, brother, what-have-you) one too many times? You get the feeling he's been out since forever, and take it from personal experience you stop thinking of yourself a "gay" anything once you get over the fact, and the movie very clearly is taking pains to show he's over the fact; his issues aren't with his gayness but other junk, so that verbal fixation betrayed, to me, a slight misunderstanding of the character, or maybe I should say a misplaced focus.
I will say I think that Rich Juzwiak's piece at Gawker on the movie over-states its defense of Hader's character's queeniness though - I went into it expecting a mincer from a 20s musical and found anything but. Milo might not be ball-scratching butch personified but he's hardly Stefon from SNL either. He seemed perfectly credible and human, indulging some of the stereotypes we all do, while defying plenty of others. (And so goes the weight of the world upon all the gay characters, having to be all gay things to all gay everybodies.)
Kristen Wiig meanwhile gives her best performance to date - watching her hone her dramatic chops has been worthwhile; there are no Seth-Rogen-ish half-grins marring the more somber moments here - you feel her pain. (So much so that I'm actually starting to worry about her - depression is a continuing theme in all of her work so far.) But I'm making everything sound too dour, this is a very funny movie too. Hader and Wiig have enough chemistry for a dozen of these films, and it pours off the screen whether they're screaming themselves raw or offering a cavalcade of fart noises.