Nobody's said this yet but it must be said: the mech looks really good. It grabs your eye when looking at the submission thumbnails, and continues to look good upon further inspection. The wings, the weapon, shield, helmet, breastplate and posture, there are so many good things happening on there.
And the trees done with that same ornamented style you use along the game page borders is a crazy idea, which actually looks good. No other trees look like that, it's a bold choice, but I think it looks really interesting and puts you in place in the game.
This is a completely different artistic direction, but look at the ground textures... In the game setting, they look like interesting ground with variably compacted dirt and bedrock. But it also kind of looks like distant parallax forest:
The same can be said for each of the ground textures, they all kind of take you to a place. Just something I noticed. Anyway, I like your pixel art. The mech is fantastic and the trees are so interesting!