From The TimeSplitters Wiki

TNT
Ammo	1 stick
Fire Rate bullets per sec/cartridge time	1
Reload Time	N/A
Damage (per Single Shot) Head/Body/Leg	100% if it sticks to player
Type	Explosive
Zoom	No
Primary Fire	Throws TNT
Secondary Fire	None
Games	All

The TNT is a powerful explosive weapon in TimeSplitters. It can be laid on the ground, on a wall, on an object or occasionally even on a character. You can only carry one stick of TNT at a time, except in TimeSplitters where equipping multiple sticks is possible.

In TimeSplitters: Future Perfect, the weapon's only appearance in the whole game is in the Scotland the Brave Story level.

In TimeSplitters 2, in Chicago on normal/hard mode, you need to use TNT to blow open the safe to get the key to gain access to Big Tony's club. It can also be used in arcade mode.

One trick with T.N.T. in mapmaker is to give story enemies T.N.T.. Because they can only carry one stick it practically makes them unarmed which will cause them to try to punch you. The explosion may kill them, however, so it's not perfect.