Simple and elegant. Clear execution of the theme with pushing your luck to try to get the orb to explode on your opponent. Mechanical descriptions when hovering cards was mostly clear, but perhaps "Release" could be changed to something like "Reduce" or "Drain" to make it clear you are taking the card's value away from the Orb's current value.
I think only a +1 charge to the orb for a magic spell is a bit low for the cost of 10 points. I think perhaps draw an additional card would be a better ability.
The music track was a bit sort and after a while I got a bit fatigued by it. Perhaps a couple more shuffling tracks could help here.
Hope the feedback is helpful :)