Trying..
 

My attempt at a few graphics. I tried to use sort of like a dot dithering(?) for the tree and monitor, and i tried to use anti-aliasing on the heart. Any comments/criticism to help my style?

The black outlines (or dark not sure) on the tree trunk stand out, but i quite like it, and the perspective on the monitor looks kinda off.

It looks nice, despite those couple of problem areas Zideruic pointed out. I also like those shields in your sig.

looks better than other graphics here.
its plastic, which is good.

It looks like the tree could fit right into the part of Gileada's server that is now open....talk to Zero :)

Graal Kingdoms. He is (was) collecting shields.

Are these pixel art? They seem like you tried to pixel these. Anyways, as for technique... the AA on the heart is messy, and looks like you just blurred the image or something. And the dithering on the monitor is just messy. There are stray pixels everywhere that don't really contribute to the image in any way. Also, you should try using these sets of lines(attached) as often as possible. It looks like you were trying to make the monitor isometric, and in that case it would be a 2:1 pixel ratio line.