Hey Nicola, there are some really nice shots here. That is one heck of an icicle in Gravity. I felt like maybe you should be further out to get it all in, but I'm thinking perhaps it's a frozen waterfall so too big?
I like the Space one, good idea to put it beside the Mandela book. Work, like it!
Gluttony is a nice idea but the squirrel is a bit low contrast against the background, and maybe could have been closer?
Good stuff though!