Composition: The composition of this photo is one of its strongest points. The shoreline is a very strong diagional leading line and it leads the eye direstly to the main subject. The red lighthouse is an awesome subject, vibrant where the rest of the photo has a very somber feel to it.
Technical: The technical post processing is very well done. You have managed to bring out the darkness of the sky, the brightness of the lighthouse, but still kept the whiteness of the snow. You might have sacrificed a little of the detail in the snow though, it does seems a little bit washed out.
Overall: I feel you were on the right track...and you knew what you wanted. Overall this is a powerful image and one you should be proud of. Good luck and happy shooting.
Nice picture. I love how the lighthouse stands out amidst all that white. Might be better if the lighthouse weren't quite so close to the edge, though.