Question: Heavy Gear II is a sequel to a game that was released in what year?

full_context: Document 1: Halo 2: Halo 2 is a 2004 first-person shooter video game developed by Bungie Studios. Released for the Xbox video game console on November 9, 2004, the game is the second installment in the "Halo" franchise and the sequel to 2001's critically acclaimed "". A Microsoft Windows version of the game was released on May 31, 2007, developed by an internal team at Microsoft Game Studios known as Hired Gun. The game features a new game engine, as well as using the Havok physics engine; added weapons and vehicles, and new multiplayer maps. The player alternately assumes the roles of the human Master Chief and the alien Arbiter in a 26th-century conflict between the human United Nations Space Command and genocidal Covenant.
Document 2: Descent II: Descent II is a 1996 first-person shooter video game developed by Parallax Software and published by Interplay Productions. It is the second game in the "Descent" video game series and a sequel to the original "Descent". Unlike standard first-person shooters, the player must control a flying ship that has a six degrees of freedom movement scheme, allowing the player to move in any 3D direction. The original soundtrack features industrial metal contributed by notable musicians such as Type O Negative, Ogre and Mark Walk of Skinny Puppy, and Brian Luzietti. The game received very positive reviews from video game critics. A sequel, "Descent 3", was released in 1999.
Document 3: Heavy Gear (video game): Heavy Gear is a 1997 computer game based on the "Heavy Gear" role-playing game. A sequel, "Heavy Gear II", was released in 1999.
Document 4: Age of Empires II: Age of Empires II: The Age of Kings is a real-time strategy video game developed by Ensemble Studios and published by Microsoft. Released in 1999 for the Microsoft Windows and Macintosh operating systems, it was the second game in the "Age of Empires" series. An expansion, "", was released in 2000. A PlayStation 2 version was released by Konami in 2001, and a Nintendo DS spinoff, "" was developed by Backbone Entertainment in 2006. A Dreamcast port, by Konami, was canceled.
Document 5: Metal Gear Solid 2: Sons of Liberty: Metal Gear Solid 2: Sons of Liberty is an action-adventure stealth game developed and published by Konami for the PlayStation 2 in 2001. It is the fourth "Metal Gear" game written and directed by Hideo Kojima and serves as the direct sequel to the original "Metal Gear Solid". An expanded edition, titled Metal Gear Solid 2: Substance, was released the following year for Xbox and Microsoft Windows in addition to the PlayStation 2.
Document 6: Metal Gear (video game): Metal Gear is an overhead military action-adventure stealth video game originally released in 1987 by Konami for the MSX2 computer in Japan and parts of Europe. Considered to be the progenitor of the stealth game genre, it is the first video game designed by Hideo Kojima, who directed many of the later "Metal Gear" sequels. A reworked version was released for the Famicom a few months later, which saw a release in North America for the NES the following year, although this version featured drastically altered level designs among other changes, and was developed without Kojima's involvement. The MSX2 version has since been given a wider release through its inclusion in "" for the PlayStation 2, as well as in its later "" for PlayStation 3, Xbox 360 and PlayStation Vita, with these later releases featuring a revised translation and additional gameplay features. The MSX2 version was also re-released in Japan as a digital download for mobile phones and the Wii Virtual Console.
Document 7: Battle Gear: Side by Side ("サイド・バイ・サイド" ) is the franchise for a popular 1990s touge racing game series whose name changed to Battle Gear ("バトル・ギア" ) in the 2000s. It was developed by Taito and was first released on arcade cabinets before being ported on the PlayStation home consoles. "Battle Gear 2" is known as Tokyo Road Race in Europe.
Document 8: Heavy Metal: F.A.K.K.²: Heavy Metal: F.A.K.K.² is a third-person shooter video game made by Ritual Entertainment in 2000. A computer game sequel to the "Heavy Metal 2000" animated movie, the game stars Julie in her quest to save her home planet of Eden from GITH, an ancient entity seeking to conquer the universe. Using a variety of weapons, Julie must now fight off GITH's forces while at the same time uncovering a secret hidden deep within the planet.
Document 9: Combat Mission: Combat Mission is the name of a successful series of computer games simulating tactical battles. The series has progressed through two distinct game engines. The original game engine, referred to as 'CMx1' by the developer, Battlefront.com, powered a trio of games set in the Second World War. "Combat Mission:Shock Force" was released in July 2007 as the debut of the 'CMx2' game engine. The "Combat Mission" games are a mixture of turn-based strategy and simultaneous real-time execution. The game environment is fully three-dimensional, with a "Wego" style of play wherein each player enters their orders into the computer simultaneously during pauses in the action, and then are powerless to intervene during the action phase. More familiar turn-based games use an "I-go/You-go" system of play.
Document 10: Heavy Gear II: Heavy Gear II is a mecha based first-person shooter video game. Set in Dream Pod 9's Heavy Gear universe, the game was developed and published by Activision in 1999 for Microsoft Windows, it was ported to Linux in 2000 by Loki Software. It is a sequel to the 1997 video game "Heavy Gear".
Document 11: Gears of War 2: Gears of War 2 is a military science fiction third-person shooter video game developed by Epic Games and published by Microsoft Game Studios for the Xbox 360. It is the second installment of the "Gears of War" series, with lead design by Cliff Bleszinski. The game was released in North America, Europe and Australia on November 7, 2008 and was released in Japan on July 30, 2009. The game expands technically on the previous game by using a modified Unreal Engine 3 engine. The development team brought in comic book writer Joshua Ortega to help write the plot for the game.
Document 12: Star Trek: Elite Force II: Star Trek: Elite Force II is a first-person shooter video game developed by Ritual Entertainment and published by Activision. It was released on June 20, 2003 for Microsoft Windows and later for Apple Mac OS X. "Elite Force II" is a sequel to 2000's "". Whereas the original game was powered by the first version of id Software's id Tech 3 engine, "Elite Force II" is based on a heavily modified version of the "Quake III: Team Arena" engine with Ritual's ÜberTools GDK, allowing for expansive outdoor environments and higher quality facial animations.
Document 13: Heavy Gear: Heavy Gear is a game universe published since 1994 by Canadian publisher Dream Pod 9. It includes a tabletop tactical wargame, a role-playing game and a lesser known combat card game ("Heavy Gear Fighter"). The setting is also known through the PC-game incarnations published by Activision in 1997 and 1999, developed after Activision lost the rights to the "Battletech"/"MechWarrior" series. It also spawned a 40-episodes, 3D-animated TV series in 2001, which featured a much simplified version of the universe developed in the role-playing game.
Document 14: World War II GI: World War II GI (known as simply WWII GI) is a first-person shooter video game set during the events of World War II. Developed by TNT Team and published by GT Interactive Software, the game was released in 1999 as the direct sequel to "NAM", which was released on July 31, 1998. "World War II GI" was the last commercially released game to use the Build engine. The player takes control of 101st Airborne Division G.I. Corporal Gerardi, sent in to wipe out scores of Wehrmacht and "Schutzstaffel" soldiers. "WWII GI" was later re-released on Steam on November 13, 2015, with Retroism and Night Dive Studios as the publishers.
Document 15: Gear Krieg: Gear Krieg is an alternate history game setting published by Dream Pod 9. It contains information suitable for role-playing and wargaming a pulp-fueled World War II, featuring walking tanks and epic tabletop battles.
ground_truth: 1999