Once you get past the fact that Space Siege isn't much of an RPG, you can start appreciating the game for what it is. The story involves humanity's exodus from earth as an unstoppable alien force called the Kerak sweep in to systematically exterminate the human race. You play as Sgt. Seth Walker, a military robotics engineer who happens to be quite handy various kinds of weaponry. He helps evacuate earth aboard the Armstrong, a colony ship turned refugee vessel, but a Kerak ship latches onto it at the last minute, allowing invaders to come pouring in. The game centers on Seth's journey as he confronts the alien threat using overwhelming firepower, a robotic sidekick, and possibly cybernetic body parts that unlock special powers.


Much of the game's hype hinges on the player's decision to install cybernetic components. Installing cybernetics isn't necessary to win the game, but they provide performance bonuses, plus a number of special abilities and weapons will require some kind of cybernetic augmentation. However, installing cybernetic parts irrevocably lowers one's "humanity," measured by a humanity bar. Having cybernetic body parts mostly works in place of a difficulty slider. Staying 100% human will result in a more difficult game and installing new parts and unlocking special powers will ease that difficulty. Now, if the game were challenging to start with. We played through as completely human, partially augmented, and completely decked out with a robotic body. Apart from the coolness factor that comes from unlocking cyber-powers and carrying around gigantic cyborg-only guns, the enhancements only make a relatively easy game easier. With the exception of the final boss, you can plow through most of the game without much trouble. Lobbing a stun grenade followed by a handful of explosives is usually enough to wipe out most groups. Using upgrade components (the game's only collectible resource) alone to boost up armor, health and damage stats work extremely well in overcoming the game's enemies. Furthermore, there are two final tier powers reserved only for characters that manage to stay at least 90% human, and they make Seth so powerful that there's practically no point in cybernetics.

The game's greatest disappointment comes from shallow treatment of the "man or machine" theme. It's fine to leave the human or cybernetics decision to the player, but the feature doesn't have nearly as much impact as it should. There's not enough NPC interaction to judge whether cybernetics are really eating away at your humanity. Characters simply chime in over the radio to comment on whether or not you should install something to get a fighting edge. The end sequence generally hinges on one decision that doesn't directly relate to cyborg enhancements, but the game plays out the same way, right down to the final boss, using slightly altered dialogue and motivation. Similarly, there are only slight changes the end cinematic and narrative based on your decisions.