Press "x" to see what items you have picked up:
Kamikaze (default k) - press this at low health and your opponent has only a few seconds to frag you
or get out of your way. Press k at strong health and kamikaze will automatically be activated at low health.
Cloak (default i) - use this to disappear before your opponents' very eyes.
Teleport (default a) - get yourself out of danger quickly.
Thunderbolt (default s) - give your opponents a shock.
Gravity Boots (default g) - now you can leap over moderately-high buildings in a single leap.
Booby trap - pick this up, and the next item you touch will leave a nasty surpise for someone else.
Healthbox - quickly racks up your health to a seriously high value.
Turbo armour - does for armour what a healthbox does for health.
Scanner - check whose lurking behind the next corner.
Jetpack - fly around with unlimited fuel.
Lightning grapple - get to those hard-to-reach spots that are otherwise impossible.
Laser trips - stop opponents from enering parts of your level
ECM module - defend yourself against homing modules
You can use "next item" (default "Q") and "use item" (default "E").