I'd expect a mockup to be "a screen-size image depicting a typical in-game screenshot of a game(/app) that doesn't exist yet".
From that perspective, there're a number of things that are surprising in your update:
- size is more of a portrait than a mockup;
- AA between the player and the background: although properly done here (imho), is usually subject to rendering engine restrictions;
- Presence of wide, black lines in what should be a background layer, that gives it undue importance compared to the foreground the player stands on;
- A quite busy seascape, just where the avatar is looking; with birds that attract the eye rather than guiding it towards the action;
- cursious things with white balls in the sky (clouds, I guess).
- a nasty dark spot near the character's ear that contradicts with the rest of face construction
- no other game-related things (items, ennemies, HUD, NPC), which make me altogether think that you're not actually trying to make a mock-up but just use that word as a placeholder...
