The visuals looks just great. You're very creative. =)
You might want to consider changing the sound at missile launch (fireball impact, I think it is), because even though I get your idea that a huge blast of ice could sound like that, I think too many map makers will associate that with fire, making the visuals and sound effect fit poorly. I would personally like something more ice-like, but of course that's entirely up to you.
Nevertheless, this is a very nice ice projectile indeed. Your projectile pack will get huge. =D