From The TimeSplitters Wiki

VR
Size	Small (every mode except for Assault), or Large (only in Assault)
Location	Virtural Reality
Climate	None
Unlockable	Unlocked by Default
Recommended Bots	Bot #1 Bot #2 Bot #3 Bot #4 Bot #5
Recommended Weapons	Wep #1 Wep #2 Wep #3 Wep #4 Wep #5

VR is a virtual map in which you play on. It consits of two bases and a middle room between them. The middle room features a series of walls and tunnels in which you can hide under. There is also a shortcut between the two bases. It is a long hallway. In assault mode, the map is completely different and is very large is size. The VR map played on all other modes is a small section of the assault map.