Visually Machines looks pretty spiffy. The 3D world, while not excessively detailed, looks OK but can't compare to the visual splendor of it's inhabitants, nor the effects of the devastation they cause. Each and every unit and building within the game is 3D modeled and quite detailed considering that at times the screen is literary jam packed with dozens of them. They're neatly textured and well animated too. On tracked vehicles you can actually see the tracks spinning if you look really close, and you can look really close as there is that 1st person mode available. Useless? Pretty much, but it's always fun to take a dive in amongst your troopers and have a closer look, especially whilst in the heat of battle.
Other units, such as Wraith Reapers have legs and you can see them run about as well, with each leg smoothly animated. And the gigantic Gorillas move in such a fashion that you can almost feel their huge weight.
Just like in Warzone 2100 though, the real treat is that of weapons fire, explosions and so on. Why? Simply because each and every shot fired lights up the surrounding machines realistically in the appropriate color, effects the lighting on the underlying surface and makes an impressive impact on the target. Some weapons, like plasma guns also feature stunning looking "laser beams" that, especially when used excessively, can paint a pretty sight. Other weapons such as missiles leave nice smoke trails and so on. And there's also an odd spark effect here and there.
The 3D engine is accelerated via Direct3D which ensures that it'll work on just about every card, and there is support for multiple resolutions for those that want to up the amp from standard 640 x 480.
Machines isn't exactly revolutionary in any aspect, and especially not in terms of sound. There's some background audio / music that doesn't really add nor subtract from the game, the sound effects are OK, but really nothing special. The voiceovers are pretty dead, but since you're playing a silicon based life form I guess you really can't expect much in terms of emotional content from the voices.