Lighthouse

The first thing that I like about this manipulation is the fact that the lighthouse has the same tones as the sky, which makes it look like a unique shot. Then, the two planets give it more surrealism.
The things that I would try to improve would be...

1. The water - it looks like it has no reflection on it - As you gave that cool look to the lighthouse, you should have given it to the water aswell(in my oppinion). But anyway, what I like about the water is the fact that´s not as bright as it was in the original image, which is good.
2. It has a lot of empty space on the upper part. The gradient is good, It really gives intensity to the image, but I feel like something is missing up there. Maybe you could have cropped it closer to the lighthouse, where is the top of the planet.

Hope this helps <img src="e.deviantart.net/emoticons/s/s…" width="15" height="15" alt="" title=" (Smile)"/>