The TS2 port found in Homefront was originally destined to be its own game as part of a project to port the game to PC, with work beginning as far back as 2008. The development studio behind TimeSplitters, Free Radical, was focused on other games at the time, including Haze and Star Wars Battlefront III. Free Radical shut down in late 2008 and was bought by Crytek to become Crytek UK. In 2014, Crytek UK shut down and the the game they were working on at the time, Homefront: The Revolution, was transferred to a new development company, Dambuster Studios, who would continue development of the game.
The entirety of TS2 was included because it was faster to include the whole thing instead of taking the time to create a bespoke version just for this minor easter-egg. So, the menus in TS2 were altered to only show 2 story mode levels and all of the other parts of the menu were hidden or removed. Again, this updated PC port was originally meant to be its own game, but was never finished and was eventually bundled into Homefront, starting as "an office joke".
"Started as an office joke, like they all do." - Matt Phillips via Twitter
Supposedly, this port of TS2 has received continued development beyond the half-working version found in Homefront. Dambuster Studio employees are supposedly have a much more polished version of the game (complete with networking support), which may eventually be released as an official remaster.
After Homefront: The Revolution was released in 2016, dataminers discovered that even though only 2 campaign missions in TimeSplitters 2 were playable, the entirety of TS2's game files were present in Homefront's files. This discovery sparked a multi-year long easter-egg hunt to try to unlock the rest of the game.
Theories were crafted and ideas were tested in-game for countless hours as players tried to crack this elusive easter-egg. Some players experimented in-game while others inspected Homefront's game executable looking for any clues as to how to trigger the full game to become unlocked. There was even an alternate reality game (ARG) conducted by a supposed employee at Dambuster Studios (the studio behind Homefront) which gave players a series of cryptic and obscure clues with the idea that once solved the unlock codes would be revealed.
Unfortunately, this combined effort didn't lead to any significant progress towards unlocking the full game. There were numerous moments of hope along the way, but ultimately the actual unlock codes were never discovered by the small but dedicated community of easter-egg hunters. There was some success in hacking the game's memory to force it load into different story missions beyond Siberia and Chicago, but the vast majority of progress was made only after the unlock codes were revealed.
The unlock codes were eventually revealed in April 2021 in a Twitter thread started by the developer who worked on the TS2 port, Matt Philips. Philips revealed that the entirety of the game was unlockable through a series of button presses (with basic multiplayer support too), but he had since lost the unlock codes. A few days later, another Twitter user, Xbox principal software engineer Spencer Perreault, replied in the thread and shared the game's unlock codes for the first time to the public (technically the codes were shared a day or two priot to that, but Twitter hid this tweet as spam).
This sparked a frenzy of activity as word about the unlock codes spread through the TimeSplitters fanbase. Suddenly, people who had no interest in Homefront were buying copies of this 5-year old mediocre military shooter just to play an HD remaster of a 2-decade old shooter game from 2002. For the first time in TimeSplitters' history, the game could be played natively on PC in HD with proper mouse/keyboard support.
The port of TS2 in Homefront was never actually finished. Since only the first two levels were intended to be playable, many major bugs were left in. Work began by the TS2 modding community to fix these game-breaking bugs so that this unique version of the game could be played properly. A small group joined to form the Redux Tech Team, the team behind this project.
- Polygon: TimeSplitters 2’s 4K port has been locked inside the Homefront sequel for years - April 9th 2021
- Kotaku: Someone Recovered The Code To Unlock A Full Version Of Timesplitters 2 In Homefront: The Revolution - April 9th 2021
- Eurogamer: Homefront's missing unlock code to make TimeSplitters 2 fully playable has been found - April 9th 2021