In 2020, 260 years before the Mox Civil War, Planet X was already having territory problems with other Alien races. A 'cyberbrain' has been taken hostage, and a rescue mission is taken to action. Angel Perez and Sebastian Photon are the two playable characters in this mission. As previously mentioned, this level supposedly takes place in 2020, however interplanetary travel seems a little optimistic for this date. The dates were decided for the original game through systematic 5/15 year gaps, so that 2200 may seem a more likely time zone. This would also bring the level much closer to the Mox Civil War. Note though, that due to the TimeSplitter penchant for altering human history, 2020 may have been the actual year, but the year of a timeline that no longer exists by the end of the TimeSplitter War.
- Planet-X Easy World Record - 36.6 seconds by Silent Thunder
- Planet-X Normal World Record - 50.1 seconds by Ace and Silent Thunder
- Planet-X Hard World Record - 49.8 seconds by Ace
Recover the hostage cyberbrain and proceed to beam up coordinates.
This is the only level in the game that starts you off in a different location depending on the difficulty; Easy places you in front of the rocky ramp leading up to the cave, Normal places you on the walkway behind the large waterfall, and Hard starts you off inside of a little alcove a short distance away from the aforementioned rocky ramp.
The cyberbrain is located inside of the caves on Easy, but Normal and Hard will take you into the heart of the aliens' headquarters.
You start the level off with a Scifi Sniper Rifle, which is useful on Normal and Hard to take care of the enemies shooting at you from afar; since the rest of the level is close-quarters, it's best to equip one of the fallen enemies' Rayguns or Scifi Autorifles after taking care of any distant foes.
Once you get inside the caves and the alien headquarters, you'll probably find that the easiest way to exterminate the large droves of aliens is by using the Scifi Autorifle's primary and secondary functions; the fast automatic fire takes them down quickly, and the secondary function's grenades can take out groups of aliens quickly, as well as any that may be hiding around corners.
To get to the aliens' headquarters without incident, take the ramp inside of the caves, and head straight from there. This path is littered with enemies that teleport right in front of you, so it may be beneficial to run down the path holding the fire button; any lost ammo will be replenished by walking over the enemies' weapons, as all weapons on Planet X share the same ammo source. Once inside the alien headquarters, you'll quickly notice that there's one or two enemies inside of each colored room. Go ahead and clear them all out, and future you will be grateful.
The cyberbrain is located down numerous flights of stairs inside of the aliens' headquarters. As soon as you grab the cyberbrain at the bottom of the staircase, a group of Green Aliens will spawn in front of you, so use the Plasma Autorifle's grenade function to take them out quickly, and run up the stairs, shooting any enemies that may be coming down to stop your escape.
The exit point on Normal and Hard is located on a walkway suspended above the rocky ramp you start in front of on Easy, where some aliens may have been sniping you from at the beginning of the level. The walkway is accessed through the red room inside of the aliens' headquarters,. Shoot any TimeSplitters that spawn in your way and touch the exit point to complete the level.