the trashcan lacks contrast, for a pickable item, imho. It would also be visually more interesting if shown slightly damaged. May I suggest
titus the fox as a reference for colours and style (trashcan in bottom-left corner).
As for the zombie sprite, I'd drop the blod spray in the regular animation. you haven't got enough frames for that. Imho, you might want to work on a 45° pose (zombie converging towards the player), as it will help depicting arms position and feet movement ... and then turn back to the front view. The most creepy pixel zombies I've fougth in my childhood were moving only one leg forward.
Lost vickings mummies did walk that way too (check the video at 04:42).
HTH.