Warhammer 40,000: Chaos Gate

Chaos Gate is the greatest* computer game ever.

*"Greatest" assuming you're into really buggy, immersion-driven RPGesque X-Com'ish turn-based grimdark scifi games, that are really buggy. Did I mention bugs?

Short synopsis

Forces of Ultramarines under command of Captain Kruger fight against forces of Word Bearers under command of Chaos Lord Zymran. Both forces want to take control over Pre-Heresy relic called the Concordat Chaosium. And to kill each other.

The game was made when Warhammer 40,000 was still in 2nd Edition, so many things are quite different, mainly weapons and psychic powers.

Basic forces

From Encyclopedia in the game:

Ultramarines:

• Tactical Space Marine Squad - A Tactical Combat Squad consists of five Space Marines. Each Space Marine is equipped with a Bolter. Any one member of the squad may exchange his Bolter for a Flamer, Meltagun, Plasma Gun or Heavy Weapon. Tactical Space Marines wear Power Armor into Combat.
• Assault Space Marine Squad - An Assault Combat Squad consists of five Space Marines. Each Space Marine is equipped with a Bolt Pistol and a Chain Sword. Any member of an Assault Squad may exchange their Bolt Pistol for a Hand Flamer or a Plasma Pistol. Any member of an Assault Squad may exchange their Chain Sword for a Power Axe, a Power Sword or a Power Fist. Each Space Marine wears Power Armor and a Jump Pack that allows him to make powered leaps across the battlefield. A jump pack has a range of 24 cells per jump. The Jump Pack holds enough fuel to jump a total of 120 cells.
• Devastator Space Marine Squad - A Devastator Combat Squad consists of five Space Marines. Each Space Marine is equipped with a Bolter. Any two squad members may exchange their Bolters for any Heavy Weapon. Devastator Space Marines wear Power Armor into combat.
• Terminator Squad - A Terminator Squad consists of five Veteran Space Marines, each wearing special Terminator Armor. Every Terminator is equipped with a Storm Bolter and Power Fist. Any Terminator may exchange his Storm Bolter for a Heavy Flamer or an Assault Cannon. Any member of a Terminator squad may exchange their Power Fist for a Chain Fist or Power Sword. Terminators may also be equipped with Lightning Claws or a Thunder Hammer and Storm Shield.
• Apothecary - The Apothecary is a warrior of supreme bravery. If a Brother Warrior falls, the Apothecary can administer to him by tending his wounds and applying battle dressings to staunch the flow of blood. The Apothecary is armed with a Bolt Pistol.
• Techmarine - The Techmarine is a priest of the Machine God skilled in the arcane sciences to the dark secrets of technology. The Techmarine is armed with a Bolt Pistol and Power Axe.
• Librarian - The Librarians are powerful psykers that use their mighty psychic powers in Battle. With all of their powers the Librarians are the ultimate warrior mystics, endowed with abilities which set them apart from their Brother Space Marines. The Librarians wear Power Armor and are armed with a Bolt Pistol and a Force Axe.
• Chaplain - The Chaplains are the spiritual leaders of their Space Marine Chapter. They perform the ancient ceremonies of Initiation and Vindication, as well as leading their brethren through the prayers of faith and sacred psalms of the Emperor. The Chaplains accompany their Brothers into war, leading the way into the ultimate consummation of battle and death. The Chaplain wears Power Armor and is armed with a Bolt Pistol and the Crozius Arcanium.
• Captain - The Space Marine Captain is the Captain of one of the Chapter's companies. He is the bravest and mightiest warrior, inspiring all under his command. The Captain wears Power Armor. He is armed with a Plasma Pistol and a Power Sword.

Word Bearers:

• Word Bearers Chaos Space Marines - The Word Bearers Chaos Space Marines, who have pledged their dark souls to Chaos, are configured into squads of five. Each Word Bearer Chaos Space Marine is equipped with a Bolter. Two of the squad members may exchange their Bolter for a Flamer, Meltagun, Plasma Gun or Heavy Weapon. Chaos Space Marines wear Power Armor.
• Khorne Berzerkers - Khorne Berzerkers are Chaos Space Marines who have dedicated themselves to the Chaos God Khorne. They live only for battle and charge into combat chanting their famous war cry, "Blood for the Blood God". Khorne Berzerkers are equipped with a Bolt Pistol and a Chain Sword. They may exchange their Bolt Pistol for a Hand Flamer or Plasma Pistol. Likewise, they may exchange their Chain Sword for a Chain Axe, Power Axe or Power Fist. Khorne Berzerkers wear Power Armor.
• Chaos Terminator Squad - A Chaos Terminator Squad consist of five Chaos Space Marines, each wearing special Terminator Armor. Each Chaos Terminator is equipped with a Combi-Bolter and Power Fist. Any Terminator may exchange his Combi-Bolter for a Combi-Flamer, Combi-Melta or an Autocannon. Likewise, Chaos Terminators may exchange their Power Fist for a Chain Fist, Power Ace or Chain Axe.
• Chaos Sorcerer - A Chaos Space Marine Librarian who Pledges his soul to Chaos becomes a Chaos Sorcerer and is gifted with new powers by his patron god. The Chaos Sorcerers command the unseen energy of the universe using it to attack and destroy their enemies. Chaos Sorcerers wear Power Armor. They are armed with a Bolt Pistol and Chain Sword.
• Chaos Chaplain - The Word Bearers are the only Chaos Space Marine Legion to still have Chaplains, who enforce a strict regime of religious observance upon their brethren. All Word Bearers are expected to spend a considerable part of each day in acts of ritual sacrifice, occult study, or decadent worship. The Chaos Chaplains wear Power Armor and are armed with a Bolt Pistol and a Power Sword.
• Chaos Lord - The Chaos Lord leads his army of traitorous Word Bearers Chaos Space Marines. He is a despicable abomination that worship the dark gods of Chaos, conquering worlds in their name. The Chaos Lord wears Power Armor and is armed with a Plasma Pistol and Power Sword.
• Bloodthirster - The Bloodthirsters are the most powerful of all Chaos daemons and the most mighty of the Blood God's warriors. Their presence radiates sheer terror, their body exudes the stink of death, and their eyes carry the promise of cold execution. In its talons the Bloodthirster carries an axe that drips blood and a long lash tipped with cruel barbs.
• Bloodletter - The Bloodletters are Khorne's Warriors of Death, the foot soldiers of his daemonic armies. Their truly horrific appearance is an assault upon reason. They descend upon their foe, driven crazy by the scent of blood, screaming with fury as they fall upon mortal flesh. They carry long, jagged Hellblades which, it is said, can drain the very soul from a man.
• Flesh Hound - The babbling tales of maniacs who have been exposed to unshielded horrors of the warp speak of the blood-red hounds of Khorne, whose howls of rage haunt their sleep and whose memory stalks their every waking moment.
• Lord of Change - The appearance of these daemons defy mortal comprehension. The Lord of Change is the wisest and most subtle of all the Greater Daemons, a monster whose gaze penetrates into the very depths of the soul, exposing its victim's innermost hopes and fears.
• Flamers of Tzeentch - Flamers are possibly the most strange and disturbing of all daemons. Their bizarre appearance belies a dangerous agility as they bound across the battlefield, spitting searing flames and roaring to life like living blowtorches.
• Pink Horrors - The survivors of daemon attacks are rarely fully sane or coherent. Scarce wonder that there are few reliable descriptions of these daemons, known only as Horrors of Tzeentch. Victims babble incoherently about pink and blue creatures, dancing monsters that bray and cackle as they whirl along dealing death with their long clawed arms. As pink horrors are struck down, each divides into two blue creatures, which continue to fight with savage ferocity until overcome.
• Blue Horrors - As ponk horrors are struck down, each divides into two blue creatures, which continue to fight with savage ferocity until overcome.
• Chaos Cultist - The vast bulk of the followers of a Chaos God are the Chaos Cultist. These crazed human followers of the Chaos Gods have been driven to the edge of madness and beyond by the terrifying sights they have seen and the unspeakably vile acts that they have carried out.

Badges:

• Crux Terminatus - This is one of the most famous of all Space Marine icons. Only the honoured veterans of a Space Marine Chapter fight in suits of Terminator armor and wear this badge. A veteran Space Marine who kills five enemy in a single mission will be awarded this badge.
• Marksman's Honor - Acts of remarkably accurate shooting or consistent performance with targeting are marked with this award. Any Space Marine that scores ten hits on targets in a mission will receive this honor.
• Imperial Laurel - Acts of valor leading to great victory are deeds rewarded with the Imperial Laurel. Space marines that complete mission objectives will receive this honor.
• Purity Seal - The Purity Seal records not so much an honor as a blessing. Any Space Marine that completes five missions with out breaking will receive a Purity Seal.