Ok,
Pretty 
The black levels are varying across the painting especially in the foreground. Remember things further away are lighter and knocked back compared to foreground. Check the fence to the bottom left as an example.
Different hot points on the castle, white, yellow, orange? uniform them a little, especially where they’re angled towards the same direction.
The lighting around the castle is pretty, but in some areas reminds me of a 1970s dance floor. See the foreground element, left.
Background mountains are a little bland, very flat, could do with a little more definition.
Purely asthetics but … is that knight stranded? poor horse
looks like he’s about to take a very big leap of faith!
One tree with leaves another without?
Waterfall to the right looks very painterly.
Why do i see so many paintings that are over sharpened and finished with a photoshop film grain?
Background sky looks nice, and over all pleasing composition, though you could do with bringing the castle more to the center, just a little.
Not bad, but could be refined 
Dave.