"The Shell upgrade." Samus selected from the list. Judging from the last upgrade, Samus figured that just choosing upgrades at random was a dumb idea, and had chosen something that sounded a bit more useful this time. She took the chip from the machine and inserted it into her zero suit.

Her zero suit began to glow, and once again began to recede, this time at the arms and legs, her feet being left bare as they shrank back into the torso of her zero suit. When her legs, arms, and shoulders were bare, the material began to thicken, while it also disappeared from the back, leaving Samus' back exposed. This was only momentary though, as Samus began to feel something growing on her back, something heavy and hard. She began to turn to see what it was, as the remaining material on her front began to harden, Samus looking at that, raising her arms to her sides as it began to stiffen.

The material hardened to a tough, shell-like material, thickening to become at least an inch or two thick, Samus starting to become weighed down by the additional weight, the hard thing feeling strangely organic and natural on her, even it if was loose around her arms and legs. When it was finished changing, it resembled a very solid swimsuit or corset design, matching her figure tightly, showing off some of her cleavage at the top of it. The growth on her back seemed to connect to it, and Samus turned to see a large brown shell growing on her back, reaching from her shoulders to just above her ass, much wider than her and extremely heavy, making it difficult for her to stand.

As Samus struggled to keep upright, it began to feel lighter as Samus experienced a slightly stretching feeling on her skin as it began to change. Her arms and legs began to take on a much tougher and more hardened look to them, losing their slender appearance as they grew thicker, showing off some muscle as underneath her shell, Samus' abdominals took on a similarly hardened look. As she grew a bit thicker, she seemed to widen as well to match the thicker limbs, pressing more tightly into the shell she was wearing, her arms and legs snugly fitting into the holes around them, while her chest swelled as well, pressing against her shell and showing off more cleavage. The additional effect of this is that Samus' new muscles helped her support the weight of the massive shell on her back, Samus easily moving over towards the mirror to take a better look at herself.

As she moved, Samus noticed that she was much less flexible with the stiff shell, and couldn't move her head back quite as much anymore, but she managed to maintain her speed fairly well, if not her grace. She reached the mirror and took a look at herself, now clad in the large brown shell, a very light brown on the front, naked apart from it, noting her much bulkier figure on her arms and legs and, even more notably, the two large grey tubes sticking out from above both her shoulders.

She wondered just what they were for, and noticed that the shell seemed to be part of her body, and wondered if she could make them do anything. She began to feel a rumbling pressure from her shell at these thoughts, and focused it, turning to face away from the mirror as the pressure quickly grew, before being forced out in the form of a huge burst of water from the two apparent cannons, thundering out it a huge wave and slamming into the wall with a loud clang. Samus managed to keep her balance thanks to the large additional weight of the shell, and was surprised by the result of her efforts, which had amounted to a very wet floor and two huge dents in the wall, caved in by the immense power of the water.

"Well, this is strange, but useful, I guess." Samus said to herself as she tried to replicate the burst, quickly resulting in more dents in the solid steel wall.