It is nice to see several new castle mocs from you.
I like the red color scheme with the trolls. In addition, the inverted duplo egg, grey flippers, and cape door are nice details. What troll moc would be complete without a skele-turkey?
The details on the wizard’s cottage that I appreciate are the staircase, canopy roof over the balcony, technic 1x1 bricks as a roof vent or dovecoat, and the wizard’s metal burner,
I am less of a fan of mixing brown and black for timbering on one building. Bay windows look better if there is more wood/timber on either side of the window to avoid a thin frame.
I do appreciate the studded landscape. It is refreshing to see a castle moc without too much snot or tile work. A few additional small rocks, leaves, sand at the streams edge, etc would add to your moc.