It doesn't technically freeze your opponent's creatures. Its a spell that puts into play every creature you and your opponent has in their hand and they are frozen immediately as soon as they are put into play. While other creatures get unaffected.
It is expensive but it has lots of uses as it can combo with certain cards like Flooding and Fractal or even Nightmare. It allows you to put creatures into play at the expense of a 3 turn penalty.
You can also study your opponent's hand if he or she is holding back creatures, then you can use this to force them to play those cards and kill them with CC especially shockwave.
If you can combine this with stall tactics, the frozen status can easily be overcome and be used to your advantage.
On the downside, you'll have your opponents creatures come active too which makes this very situational to use. You can use this one sided, if your opponent doesn't have much in their hand when you play this.
The cost can easily be adjusted though