Here is the 3 Aliens piece so far, I added a catwalk in the upper section of the doorway to fill out the space above the large aliens head.
During my last session I voiced my annoyance with the guy in the bottom left of the picture and it was agreed to give him a more dynamic and alert substance to his pose as he looked a little static and not really responding to the scene unfolding in the doorway.
The image is not completely done yet as I still have a fair few areas to refine but I am happy with it so far.

Here I did some quick colour roughs of a type of tram station, that utilises high speed transports for shipping the prisoners to the different sectors of the prison.
Although I liked the concept It was pointed out it focused to much on the environment and did not show much of anything regarding the prisoners.

My second idea borrowed from the first by having the aliens being roughly shunted through the main entrance to the prison.
The main changes consisted of making the doorway a much more interesting shape and allowing for a grate number of vastly different shaped aliens to pass through its foreboding archways.
I completely dropped the idea of the trams at least for this image, to better focus the attention on the aliens and guards in the scene.
In the background you can see I brought back an idea I drew up previously of the shuttle that had dropped off the prisoners which is now blasting off back to the space stations in orbit.

After going over my designs again I am beginning to have second thoughts about the Protagonist alien I'm not satisfied with my current design for him.
My vision of this character is a mysterious and shady character who is helping the human protagonist for unknown reasons after aiding him through the complex after the corruption has taken most of the Prison.

Upon finally meeting the mysterious alien the human is shocked to find out he was being aided by prisoner who has somehow escaped from his prison and taken over the control room on Deck A4050.

I am yet undecided if this should be the VIP prisoner instead the main threat I had originally planned.
The threat could possibly be a largely unknown entity developed within the bowls of the prison by the Head Warden's personal scientists.
Somehow this VIP prisoner is connected to with Head Warden and the strange experiments being conducted in the bowls of the Prisons inner sanctums.

During The feedback session a valuable point was mentioned about the lack of humanity or expression present in my would be alien protagonist.
In my future studies I shall re work my current design to try and add a seance of personality that is readable and recognisable to a human audience. As well as concept the abilities this alien will posses, I wanted this character to exhibit something akin to telekinesis as well as other psychic esc abilities such as telepathy and perhaps some type of healing.

Most importantly these abilities are fuelled by a type of energy that is harnessed in all living things. The connection between the protagonists power and the universal energy is noticed by the Head Warden, who just so happens to be a half insane, sadistic, madman currently living out a life long obsession with the discovery and harnessing of said energy.  

(Bottom)
 this image was some concept sketches for the main protagonist of the story a telepathic semi aquatic native of the planet the prison is situated. His species is heavily despised by the local humans due to a wave of xenophobia that has swept throughout the colonies and as such his race suffer greatly at the hands of the prison guards especially when those hands happen to belong to the head warden.

(Top)
I created a more refined image of the top right concept in the previous image as it fitted best with what I was looking for in my protagonist alien.
It was very important that out of all my aliens this guy has to vaguely resemble a human at least emotionally more than any other alien character but still remain quite alien at the same time. I found that by removing his mouth and focusing on his eyes and brow line I can still give this guy some powerful emotional expressions to guide the viewer visually through this guys story.
I will develop this guy further to breath some life and character into him and to also refine the design to enhance the visual interest as I feel he is looking a bit plain at the moment.