This is a very well done piece. Your use of color is nothing short of masterful, as you contrast the vibrant, almost threatening colors of Samus herself with the more calm, organized hallway behind her. It's even better considering that you're using the armor design from Other M as the base, which is quite understandable; in the beginning cutscene, Samus is clearly using this incarnation of her now famous armor, and for that, points to you. Now, the only thing I'm wondering is, what is that hexagon shaped blue thing above Samus' head? Is just decoration, or does it serve some other insideous purpose? I, and I am assuming other viewers, don't know what it is. And that, I think helps sells this as a wonderful piece of not only fan art, but art in general.
First off, I'd like to start by saying I'm a fan of your work. Secondly, I'd like to point out that I'm aware this is an older piece, so I'd like to restrict my comments to things which I feel might help you push even your more current artwork, as you've grown lots since this and therefore nitpicking about small stuff you've already grown past isn't very beneficial to you in any capacity. And third, I'm also a big Metroid fan, so I hope you appreciate my feedback on this piece.
On the technical side, two things you [still] need to work on are your edges and values. You have really messy, muddy edges everywhere. Your sharpest area is on the far thigh, which also has the most value contrast, so my eye goes there and likes to sit in that area moreso than looking at the rest of the piece, and it keeps going back there. You have loose edges in most of your pieces, and even in your newer work, where areas of [supposed] focus have the same edge quality as things way off in the background, and also similar values. This kills a lot of the depth in your images and flattens your pieces. It's a good start, but what you need to do is go in and fix things so areas of interest have nice, clean edges and other things can get blurred out or vignetted. Remember that as you go back in space, atmosphere will make your values and hues diminish into the distance. To do the fix, just use the lasso tool to extract your figure onto its own layer via CTRL/Command+J and use either the lasso or hard eraser to clean up the edges. Then, for elements in the distance, use levels and on that bottom gradient bar, slide the black one over to the right, to remove the darks as things get lighter the further away from you they are. You can also extract the midground and background and use this in much the same way, to create varying levels of depth and edge work. Your recent "Mech Warfare" image has these same issues, so you can pop your foreground figure a bit more by cleaning up his edges, and then use the aforementioned technique of removing the darks to push the other two mechs into the background and create some depth between them, making the humanoid one even further into the distance. I see you tried to use volumetric fog to separate them but the piece is still flattening out because the values are too dark considering how far away they'd be.
You also have some lighting issues, like you haven't committed to a single light source, so different elements in your image are lit differently. For character work, I get it, you want to have the upper body lit moreso than the lower body so more attention goes to the face. I see you tried to have some reflected light from the environment on her helmet, which is good. However, even elements on Samus' upper body aren't obeying a true top-down light source (i.e. the helmet and shoulders have a top-down light source, but that isn't being applied correctly to anything else, like the green cannon or her orange arm, which both seem to have their own independent light sources). The upper legs are also not receiving light with the same light source as the upper body and you don't have any cast shadow, from her arms onto her abs and leg, or from the silhouette onto the ground. Remember, form shadow = soft edge, cast shadow = hard edge. You are also painting with harsh blacks, which don't occur in nature. The darkest areas should be your ambient occlusion, in the cracks between plating and under her feet to make her grounded.
Compositionally, your background elements are also framing the figure too much. You have architecture that is practically outlining her arm cannon and elbow, her opposite shoulder, and both her thighs. This creates almost a sort of tangent and is a bit uncomfortable for the eye. Overall these technical aspects are causing a flattened image, and the lighting is not establishing a clear focal point. I'd add that the blue halo-like shape is distracting and competing for attention because it's a rather prominent structure in your composition.
I'm seeing these things in a lot of your work, including your more recent work, so I think these are things you could work on to improve. Your lighting and edges especially.
I did a quickie paintover for you. Here you can see your original next to my paintover for comparison. katmachiavelli.deviantart.com/… Note I cropped a little off the top, so the eye line can fall on the rule of thirds, to make it a little more pleasing for the viewer. I hope it helps as a supplement to what I'm writing here.
Now, the technical stuff impacted both the technique score and the impact score (as the lighting lessens the impact) but as for vision and originality... I mean, the idea of putting her in a Halo-like Forerunner-esque environment is interesting, but the way it's executed doesn't show much thought into how or why you chose to put her there. It feels like it's mostly a beauty shot of the character, in a fairly stock Samus pose. The heavy emphasis on this particular background makes it seem like it's trying to be more of an illustration, but there's no story to be told here. She's not exploring this new environment she's in, or acting cautious like she doesn't know what's going to jump out from around the corner. She's just posing in a stock Samus pose in the middle of this hallway for no good reason. So the overall vision has potential, but the originality of what you've done just feels like something we've seen ten billion times before in marketing art of the character, and the background seems rather derivative. I know that might sound harsh, but it's true, and I'm calling it like I see it, hence why the score is the way it is. If you took the time and effort to design some Chozo temple courtyard or something instread - the sort of thing we hear about but never really get to see - I'd be more inclined to give a better score for originality and vision.
This is unfortunately something I also see a lot of in your work. In your Mech Warfare pic, we see the camera looking at this one guy and two big robots shooting at something off-screen. We don’t see what they’re shooting at or why. It’s the equivalent of Michael Bay panning the camera away from the cool giant robots in Transformers to focus on the army men shooting their guns. In illustration, you should be thinking about what story you want to tell to your audience, so you’d want to pan the camera out and get a nice, good establishing shot on what’s happening so we have a bit of context. If you isolated the army men shot out of its context, it just looks like a close-up of army dudes shooting their guns. It’s more interesting when you know they’re shooting the guns at giant alien robots that transform. In a shot like this, though, you have to decide what you want to communicate with the piece, which isn’t clear other than “Samus in standard stock Samus pose,” which is why I docked points from vision and originality.
In my paintover, I added in some smoke from her arm cannon, which makes it seem more like she's cocking her gun arm after having fired a missile at something, and one eye can be seen through the visor like in the intro to Super Metroid, with an intent-driven gaze. This at least provides some context to why she's standing like that, and tells a bit of story. Even with the faded background, it tells something about the character and her personality. Additionally, since I faded out much of the background to focus on the character and emphasize a top-down lighting, the blue shape got faded out and no longer competes with the character. Having a smoke trail there (which I could've done better if I put more time into it, but it's just a quickie paintover) fills that space as a compositional element, so it doesn't feel so empty.
At any rate, I hope this helps It’s got the start of a good piece, but it needs that extra thought and love in the right areas. Think of your story, think of how you want to tell it, and then use lighting to describe form and edges to pop things into focus.