Hey there! Good job here! However, I think you could push the mood and lighting a bit further. You mentioned that the intention is a sunset, and the colours already look like it, but you could push them a little more. What I did was adjust a Colour Balance layer in Photoshop to make the midtones and lights a bit more warmer and the shadows a bit cooler, and then paint over it a bit to adjust certain areas. On top of that, I used a layer set to "Hard Light" and painted with an orange colour to push the lighting further and enhance that sunset mood. I didn't do it here, but you could also paint the shadows using purple or lilac tones to avoid making everything look monotonous and add a bit more color vibrancy. The way the character is holding the helmet doesn't look entirely realistic to me... Ideally, or at least I think it would look more believable this way, the hand should be holding the helmet rather than having it simply positioned between the arm and torso. Hope this helps!