Thanks for showing me my mistakes.
The palette is @grafxkid's Generic15.
I love the texture on the pink planet. The explosion / black hole is a little unclear. It looks like it needs better blending between the jagged bolts and the circular explosion. Also try to focus on the negative space and how it interacts with your focal points - as the image looks both sparse and crowded.
Excellent choice of colours. What's the palette?
I hope I wasn't too blunt! It's a lovely work :)