Alright, lots of different thoughts. I apologize for this being a bit scattershot in terms of advice.
Looking at your portfolio, the Wendigo stands out as the best digital painting, probably because it feels like it's the most intentional in terms of use of colour. The other drawings feel a bit more naive in that the colour shade ramps feel flat due to use of more or less a single hue from light to dark. I recommend reading this lovely tutorial to help address what's going on there. Lots of other good stuff in there as well, it's basically the link I send to anyone who ever asks for advice about art.
Your 2D character drawing is very lineart focused. That is, they all seem to follow a process of lineart -> colour layer -> done. I think perhaps you should show an ability to use some different approaches to rendering, like something more painterly, something more vectory, and maybe even something more pixely; it's a fairly narrow range right now.
In terms of anatomy/aesthetics, the characters mostly seem to be, hmm, like there's a tall & thin manga/anime thing going on. Not a bad thing to do, but you should be able to demonstrate a range of styles above all: how about do a realistic character, a super cute character whose head is like the size of their body, and .. something else, maybe something more monstrous? .. in addition to the willowy anime character look. Show your range!
The super extended breakdown of weapon art is actually pretty interesting because it really shows some thought about the process. It'd be completed by (say) a mockup showing how these weapon assets are meant to look when integrated into an actual game scene, because what's missing here is letting the viewer know what problem you're trying to solve with your designs.
A cool link I'd recommend: Gausswerks redesign of Jericho characters: this shows a process of character design from start to finish and explains why the choices are made. It's a lovely piece of work - if you can do something like this, show the process of designing a character for a game (and show why), it'd make a great portfolio piece because it shows you can take in project goals, consider options, then make a decision about how to approach aesthetics in a way that addresses the project requirements.
So, to those ends, consider entries in your portfolio that show what you can contribute that's part of making a game. Drawings of characters are fine and all, but the question is how do they apply to a hypothetical game project? How are you showing you can create 2D assets that can be used in a game? So two angles here, 1. is to show the process of concept work (as per the Gausswerks link) where you design something to solve a problem, and 2. also show some hypothetically ready-to-use art to demonstrate your ability to produce working assets.
For the latter, showing your ability to create ready-to-use assets, it may be valuable to have a look at (for example) the Unity Asset Store section focused on 2D game character art: https://www.assetstore.unity3d.com/en/#!/search/page=1/sortby=popularity/query=category:139 ; If you can do art that's like a set of those that actually sells for money, then you'll be showing you're ready to be hired. And again, you want to show versatility; an amateur draws only what they're inspired to draw while a professional makes it their business to be able to draw whatever is needed whenever it's needed.
And you mention doing environmental art; that'd be good. More range is always better!