For one thing there's the title. 'Gravity' means both seriousness and what brings us down to Earth. It's also the force that makes things come together (which might make us think of The Beatles and Primal Scream, but that's probably just me). The movie is a plea for seriousness, for a fantasy-free vision of what matters (especially our planet and life itself) and what we are doing to it (especially through violence and disregard for the environment), and for a sense of international unity. The life-threatening problems faced by astronauts Sandra Bullock and George Clooney are caused by the shooting down of a spy satellite creating a domino effect with other junk in space breaking up and smashing into still more satellites and debris. Hope comes (practically) in the form of the Americans' being able to use Russian and Chinese spacecraft, and (spiritually) in the form of Jesus and the Buddha. We all need to help each other despite national differences, in other words, and a little faith wouldn't hurt.
Secondly there's Clooney himself, who starred in the re-make of Solaris. Of course Gravity isn't as good as the Tarkovsky original, and the reference to a cover version of one of his films only emphasizes the point. But still, the fact that Clooney is there in space makes you think of Solaris and therefore of both the mysteries of Tarkovsky's film and the inferiority of the Clooney version. The deep and the second-rate, the artistic and the commercial. Like it or not, the film calls these thoughts to mind (unintentionally, I would think, although maybe it's a brave confession that it is all these things).
Third, Clooney's character is called Kowalsky. So we're in Vanishing Point territory--the individual versus the world (or at least the man), the quest for freedom, "the last American hero." He is heroic and American, but the reference doesn't do much except give the character what little bit of a third dimension he has. (It might make you think of Primal Scream again, but I doubt that's intended.)
Finally, The Smiths. In a moment of despair Bullock's character (Ryan Stone, presumably meant to be as generic a name as could be found) asks someone to "sing me to sleep." (I assume this is a deliberate reference, but who knows?) There is some treatment then of the ethics of giving up, the problem of evil, etc. Against the pain of pointless suffering is weighed the beauty of the Earth. Beauty wins.
And that's about it. It's a nice-looking film, with fun 3-D effects, and a very noticeable soundtrack. It gets loud right at the end, but mostly it sounds like the kind of orchestral sound you get on some Spiritualized songs. Which is kind of appropriate.