Reshaped the whole thing and recoloured it according to happymonster's pallete. Only extra colours are the grays in the gun and the green used for the chest crest and eyes. Opinions?

I would like to create some more sprites for the various races in the warhammer universe, although I'd need some great model references.

Well be aware some models vary according to the editions. Your space marine seems up-to-date, but as you might have seen on my terminator thread, sometimes the armor can vary a lot in therms of size and shape. That's also one of the reasons of why I'm having such a hard time with it aswell. For other space marine essencials you might want to create a Dreadnought, a Predator Tank, and obviously, a Terminator, since they're the most known units of the space marine army. As for the Orcs I recommend Shoota Boyz, a Killa Kan, Nobz, and a Wartrakk

but at the size you're working it's too small too get away with it not being stylized, the thing about spriting for a game is to create readability.

Yet remember the sprites are zoomed while in game.

Therefore it is much more difficult to draw in as much detail as the sprites you've just linked to. Could we see some of your other graphics? because I much prefer the edits with the larger helmets to the version you are currently working with.

But not impossible. If you take a look at any of the chaos engine character sprites, you'll realize how the artist managed to create a lot more intricate details at a smaller scale with no more stylization the one I'm using. Plus by observing the basic shapes of the terminator armor itself, one can realize they're a lot more straightfoward to come up with than certain, let's say a more human or animal shapes. the details being mostly concentrated on highlights and reflections which once again are not impossible to create at this scale.

Could we see some of your other graphics?

Pardon me? I thought I mentioned at the beginning of this thread this was my fiirst sprite

One thing that I've been doing wrong so far was to present it in a light or soft coloured background. The itself we'll be featuring very dark environmets, similarly to space hulk, so as soon as I accidentally dropped a black paintbucket on the background, magic happened and the sprite suddenly looked a lot better. Added darker shaders and remade the helmet. He looks like he means business now. Should be adding a few more black shaders. Also added mdchristie's gun (hope he doesnt mind), reduced the torso size and the arms a bit. Reversed the hunchback.

Well, cartoony reads really well.  You might dodge that, but i would urge you to examine quite closely the shapes that you make.  There are a couple of problems with the sprite as it is now, notably that it's rather flat (the contrast added by happymonster  was a good solution) and the face you've got which drops off chinless makes it look a lot like a bug.  Actually his whole form reminds me of the alien brutes from half life painted red

The face does indeed look a bit bug like but alternatives so far, are either too big or look like something aswell. Eyecraft's version seemed great until i recognised a lion-like face on a closer inspection. I'm still tweaking it over and over, but i've realized that you either had the breeding mask thing and leave out the chin or put the chin and leave the mask part of, which is bad aswell. The trick is to show a bit of both, but so far I've yet to realize how. As for contrast and highlights there are still some things left to be shaded, such as the arms.. I'll probably attempt to reshade the pauldrons too. A problem with adding darker shades to the chest was exactly another bug related problem: harder inbetweens make it look like a red beetle or a ladybug. Also keep in mind this sprite model is supposed to be recoloured according to other chapter patterns/colours, so overshading might turn up to be a bit of a risky choice for me :p.

On a closer inspection I've just realized I need to rearrange the hunchback aswell. and change it back from a ^ to a V perspective. The leg stance could use a tweak aswell- Is not as quite as good as I thought it was.