Converge shatter

[xouman]

Painful Truths uses the new Converge, a kind of sunburst, and this card came to my mind

Converging shatter   
Instant
Destroy X non creature artifacts, where X is the number of colors of mana spent to pay this spell.


The main objective, of course, is to crush spheres. Making it able to destroy also creatures feels too much, even as a sorcery.

Too powerful? Too bad? Stupid design?