Intravenous achievements

Kill 5 enemies with a shotgun in 10 seconds.

Kill 3 (or more) enemies with a single frag grenade.

Kill someone with the shrapnel from a frag grenade.

Neutralize someone while they are under the effect of a flashbang.

Get killed by a door bash.

Take out an enemy that's investigating an enemy body.

Kill yourself with your own frag grenade.

Complete a level without being detected.

Knock an enemy out with a door bash.

Complete a level without killing anyone.

Complete a level without taking any damage.

Kill 6 enemies with guns in under 5 seconds.