So I kill Slone and her friends, then I go up to the weapon, open the hatch and then a big 'U' appears (my use key), so am I supposed to tap it really fast, or in time with something, or hold it or what? I've tried three times and nothing has worked. Can anyone comfirm exactly what to do?
The real question is why would they put this mechanic at the very end of the game and never have it at any point up until then. It's madness. Also, pointless.