Looks promising but you should add some additional lighting like some fireflies or shining clouds or even moonlight. Also some volumetric lighting could add to the image. Water shouldn’t be that clean - add branches, little plants or anyhitng else there. The fog would look more believable if it wasn’t homogeneous but denser or less dense in some places. The bridge could use some more modeling - any variation will help - break some of the planks, leave out some, make parts fallen to the swamp… And I think you should add an environment - it’ll help your water so that it has something to reflect. The moon would be nice I think because it could be reflected in the swamp. Finally I’d suggest adding some color corrections and shifting colours to blueish tones. Looking forward to seeing the final image.