Very nice conversion. As was mentioned, the space for the gun carriage could be used for something. Barbie heads maybe?
But yeah, the only critique of it would be that in the end it definately needs more skulls and blood. The actual model I believe has so many skulls on it that I probably wouldn't buy it because of the fact all the rest of my time for all eternity would be spent painting a mountain of little tiny skulls.
"There is a cancer eating at the Imperium. With each decade it advances deeper, leaving drained, dead worlds in its wake. This horror, this abomination, has though and purpose which functions on an unimaginable, galactic scale and all we can do is try to stop the swarms of bio-engineered monsters it unleashes upon us by instinct. We have given the horror a name to salve our fears; we call it the Tyranid race, but if it is aware of us at all, it must know us only as Prey."