What are the differences between movie!Snape and book!Snape?

No difference.



His height: Alan Rickman is taller than him.
His eyes: Book Snape has black eyes. Movie Snape's are brown.
His hair: Book Snape has greasy straight hair that hangs around his face like a curtain. Movie Snape's is nice and bouncy, and I want to run my fingers through it.
His general appearance: Book Snape's appearance is open for interpretation, really, and I'm not saying any more than that here. Movie Snape...well...it's Alan Freaking Rickman. He's a beautiful man.
Book Snape is shouty. Movie Snape isn't. In fact, we only really see him shout once, and that's the Whomping Willow Incident.

he's more cruel? I don't know...

well i always though books snape was less subtle than the moive snape-the movie snape was always more reserved and never really got violent and out of control-his trademark was not moving his lips much where as in the books-he's more...how should i put it "alive"-he goes completely mental in P.o.A when he hears sirius has escaped!! Pherhaps the book version is less attractive and might be a little nastier directly to harry as in really mean and cruel where as in the films it's more of a comedy act like in Slughorn's party and he seems more sarcastic with him than really really hating harry!