Okay Nepycros, we get the point. Ironic that this card counters Gravity the best when it is Gravity, and can be pretty powerful overall lategame.
Still, I like the concept, although it may be really strong considering what it does to higher cost creatures. Now, for the real question : is this card OP because of it's strong effect on high-cost creatures? I'd say that with all the examples being provided here a +1 cost wouldn't hurt.