So, er, with all that misinterpretation I had done (see part 2), what did I expect to have happen? Well, the below is what I thought Disney were trying to lead us towards. . . (ignore the fact that I wrote this up like it's a bad edition of Shakespeare rather than a screenplay. It could have been worse, though - I started out with full narration in 3rd person omniscient!):

HANS is kneeling on the floor in front of the fire, watching ANNA, who is lying on a chaise longue

ANNA (hands folded over her heart, her expression one of pleading): She froze my heart, and only an act of true love can save me.

HANS (eyes growing wide): A true love's kiss.

HANS caresses ANNA's cheek, and gently tilts her head back. ANNA closes her eyes as HANS leans in to kiss her as the music swells to a crescendo.

They kiss.

Nothing happens.

The music stops.

ANNA (bewildered, her eyes searching HANS' face): Nothing happened! It didn't work!

HANS (wearing a resigned expression, sighs): No. It didn't.

ANNA: I don't understand (looks to Hans, and continues, desperately) Why didn't it work?

HANS: Because, Anna. I'm not in love with you (dramatic pause) – I'm in love with your sister.

And there you have it. The so-obvious-it-wasn't-even-a-twist twist I thought they were planning.

Regarding the actual twist, I still don't get why he tried to kill her instead of trying to kiss her - it would be in his best interest to keep her alive until they were publicly married, and even better if he waited to get all murder-y until they had an infant child for whom he could be regent. But I guess evil is evil? Or something? Sigh.