of non-linear branching storylines, which it combines with the concepts of time travel and parallel universes, expanding on the Chrono series. Radiant Historia takes it much further by giving players the freedom to travel backwards and forwards through a timeline to alter the course of history, with each of their choices and actions having a major effect on the timeline. The player can return to certain points in history and live through certain events again to make different choices and see different possible outcomes on the timeline. The player can also travel back and forth between two parallel timelines, and can obtain many possible parallel endings. Square Enix's PSP version of Tactics Ogre: Let Us Cling Together, released around the same time, featured a similar "World" system that allows players to revisit key plot points and make different choices to see how the story unfolds differently. Atlus title Growlanser IV: Wayfarer of the Time (2012) features a unique battle system that blends turn-based and real-time strategy. The player controls each character in turn, but the actions play out in real-time. Imageepoch's upcoming Saigo no Yakusoku no Monogatari (Final Promise Story) for the PlayStation Portable has a strategic command-based battle system where enemies learn from previous skirmishes. The characters can also die permanently during gameplay which in turn affects the game's storyline. Western personal computers Many Western PC games have utilized this genre for years, as well. Western games tend to have stronger military themes, without many of the fantasy elements often found in their console (and mainly Japanese) counterparts; as well as greater freedom of movement when interacting with the surrounding environment. Notable examples include the Jagged Alliance series (1994-2018) and the Silent Storm series (2003-2005), with many titles owing considerably to the X-COM series (1994-2016) of strategy games. In fact, Western PC games in the genre were largely defined by X-COM in much the same way as Eastern console games were by Fire Emblem. 1990s Incubation: Time Is Running Out (1997), part of the Battle Isle series, was one of the first strategy titles to use fully 3D graphics and support hardware acceleration on the 3dfx Voodoo. Other titles in the series are mainly tactical wargames featuring vehicle combat and base capturing. The game was generally well received by critics. Gorky 17 (1999, a.k.a. Odium) is a tactical RPG by Polish developer Metropolis Software featuring elements of survival horror.