Firstly my apologies for drawing the wrong gender, but I like drawing girls so that was half the reason I made this edit
Firstly, it looks like his right (our left) eye is about to fall off the side of his face. It's good to make sure you've got some skin showing at the very edge of the head since peoples' eyes are more in the middle of the head, and it only makes sense. Secondly, the bridge of his nose seems to be too flat; I understand this is anime, but even though it breaks most anatomy rules, you need to know how to break them to make it look good. Thirdly, his hair looks too much like rolls of paper, and not quite hair-like. It's good to make each section bleed into the other just slightly to keep it unified and hair-like. Your hair also seems a little lopsided. Fourthly, he doesn't have much of a chin, and no lips. Lips can be hard to pull off, since you need to be really subtle, but it's possible, and looks great if you can get it. Fifthly, the heck it's a neck! It connects to the back of the head, not the bottom. The very front of it is actually right under the very back of the jaw. Sixthly, the eye sockets would leave a noticeable cavity in the right (our left) side of his face. Seventhly*, the proportions are pretty anime right now, and I think that you should try drawing more realistic faces.
That was the anatomy I hope that I fixed up. I'd suggest you do some life studies and maybe pick up an anatomy book to read if you wanna get really great at drawing faces.
* I tried to keep your proportions since I didn't want to deviate too much from the vibe of your character.
Note:To make this look male, just try to get some more sharp angles, a more defined neck, and a more pronounced jaw.
Now I think I'll talk some pixel-tech at you.
So firstly, there's a lot of banding going on everywhere. It's most noticeable on his jawline, but it's hiding in little nooks and crannies everywhere. Try to stay away from long lines of a single shade; if you do that, chances are you'll dodge a lot of blurriness. Secondly, you're spreading your shades out too evenly. I know it feels like a sin to abstain from using all of the colors you have everywhere, but if you bite your lip and choke your cat, you'll be able to overcome that and be able to reserve some of your colors for the more attention-hungry and important parts of your piece, and make it look amazing*. Thirdly, this goes pretty well next to secondly, your pixel clusters (the globs of pixels like the highlight on his cheek left (our right) cheek) are a little too small in some places. Don't be afraid to make some sharp edges and let the pixels shine through in all of their glory. You'll be surprised at how good they can look sometimes, and how much more alive your art will be without all of that super smoothness.
*Please note that my edit does not exploit what I've been talking about enough to be even close to amazing, and I definitely don't think it does. I just like to be emphatic