Last Blood

At the end of Guns of Stygia, kill all the enemies on the walkways before the explosions do

Hell Razor

Kill a Burnout using the helicopter that arrives in Crash Site

Heart Attack

Kill a Boss using the Hot Dog cart in the Hotel Elysium map

Bell End

Kill 5 enemies at the same time using "Dung" in the Villa map

Extinguisher

In the Sewer map, kill 5 enemies in 1 wave by setting them on fire then extinguishing them

Fast Track

On Mean Street, kill all the snipers on the rooftop before the DNA bomb explodes

Up-Lifting

On Monorail Factory, kill all enemies whilst riding the lift

Environmentalist

In the Rock Quarry map kill an enemy using a Mine Cart, Oven, Fan, Smasher and Lava Cart in one wave

Beat 'em down

Kill every enemy in a wave using only the Teleportation in the Ulysses map

Barber

Kill an enemy by thumping them into a helicopter in the Mini City map