Saying that Space Siege is Dungeon Siege in space would be like saying Gears of War is just a third person version of Unreal Tournament III. The games share technology, a similar control scheme, and similar perspective but that's about it.
In the future the Earth reaches out to the stars. Unfortunately for us we run into the Kerak while colonizing a planet. The Kerak realize that humanity isn't mostly harmless and decides to eradicate humanity not only from the planet but from the universe itself. They track humanity back to Earth and destroy the planet. Fortunately humanity sees it coming and manages to get a few large colony ships off before the planet is cleared out for a new interstellar highway. You play Seth Walker, a military soldier on the Armstrong, one of the ships who must help keep the ship and the last remnants of humanity safe so they can find another home (kind of a reverse Battlestar Galactica if you think about it)
Unfortunately for the crew of the Armstrong, the Kerak manage to attach a boarding pod to the Armstrong before it makes the jump to hyperspace. This is bad because the Kerak tear through the crew like a five year old at Christmas. It's now up to you to stop the Kerak and help preserve the safety of the last of the human race. There's a bit more depth to the story in the game but I don't want to spoil a fairly solid plot line. It's not or Bioshock or Half Life but the the plot of the game is interesting enough to keep you engaged as you play through the seven to ten hours of gameplay.
If you've played one of the Dungeon Siege games or any other third person action game you'll feel right at home with the controls of Space Siege. Left click to move and right click to interact with items. You can feel the lineage of the Dungeon Siege games in Space Siege but the game is much more focused and streamlined experience. Unlike the Dungeon Siege games, Space Siege is very linear as you will only have one mission at a time to focus on. There are secondary missions in the game but most of them are within short proximity of the primary objectives that they don't really feel like secondary missions
Gameplay is mostly walking from one part of the ship to another and killing things along the way. Once the objective is complete you return to the central hub to get another task which will require another trip out to the ship. While this may sound dull the action can be fairly intense at times as the game constantly throws different assortments of of enemies at you. Along the way you'll collect parts which allow you to upgrade yourself and your weapons. There's not a huge assortment of weapons but it was enough to keep me engaged in the game.
Another change from the other Siege games is that you ride solo in Space Siege. It’s just you and your robotic helper HRV (pronounced Harvey). During the game I alternated between calling him DAWG and HLPER depending on if he did something smart or stupid. As you progress through the game you can upgrade HRV with new weapons and abilities. When HRV dies (and he dies a lot) you can go to a unit located around the ship and get a new unit to replace him. This eliminated any real attachment I had to the unit which consequently led me to using him to clear out minefields (to save ammo) and to act as a bullet shield in larger firefights.
As you progress through the game you are offered the chance you upgrade your self with cybernetic enhancements which are scattered around the ship. Each upgrade will cost you a part of your humanity which leads into the core question of the game “What makes you human” The short answer is that cyborgs get the cool guns full humans get the chicks. I played through the game as a “pure” human and while challenging in sections the game wasn’t overly really that difficult. I then went back and played the game with all the upgrades and the game was noticeably easier as you get a chaingun that tears through about everything you come across. There is some philosophical discussion in the game but you can skip the talky talky stuff to get back to blowing stuff up if you are so inclined.
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