Spacious and smart
The right side of the case lacks the blank side panel commonly supplied with tower enclosures. Instead, the Mars has a vent with what looks like two fans hiding behind a grill. This intake provides additional cooling for the case's hard drive bays, breaking up an otherwise-uniform expanse of brushed aluminum.
The left side isn't all that different, save for the rectangle of interest being significantly larger. The "grill with a view" incorporates a handle for removing the entire side panel right into the design, maintaining a look consistent with the rest of the case. I'm not as partial to the raised ridge along the edge of the cutout, but it's necessary for the manner in which Gigabyte has chosen to make this mesh grill interchangeable with a clear plastic window.
While it might first appear the feet of the 3D Mars are horribly inconsistent in the last two pictures, the truth is that each one can be rotated either to stick out for extra stability or to swivel in for a cleaner look. I've only seen this on a few other cases before, so having the choice here seems like a nice little luxury.
Before diving inside, we should take a quick look at the back of the case. Here, it becomes clear that the 3D Mars is a significantly taller case than your average mid-tower. The designers have incorporated two 120 mm fans for exhaust, and that takes a lot more space than your average mid-tower provides. In the bottom right-hand corner of the case are two rubber-clad cutouts designed to hold water tubing for an externally-mounted radiator. Unfinished steel cutouts could cut into the soft, flexible tubing used in most water cooling setups, so by lining the holes with softer material, the coolant tubes can be held in place securely without risk of damage to them.
The left side panel of the 3D Mars unlatches and comes off with a strong pull, and it feels solid even when removed.
A crossbar that supports the power supply and gives extra rigidity to the chassis might at first seem like an annoyance, but the crossbar is removable, and it doesn't really get in the way given the sheer height of the enclosure. Each of the external drive bays has a sliding plastic lock that holds drives securely without the need for tools. The two fans that were somewhat visible from the right side of the exterior are now easier to see, but they stand out even more when we remove the side panel from the right side of the case.
The fans are 80 mm Everflows with half the depth of a usual case fan, but they're not the only prominent feature here. Two large foam pads cling to the motherboard tray toward the bottom, providing a measure of vibration dampening between the case wall and interior. There are also three small cutouts near the top of the motherboard tray that allow cables to be routed behind the motherboard. However, these cutouts are too small to accommodate even SATA power and data cables, so their utility is limited.