Here is the full list of all 24 Carnage Playtest achievements.
Accumulate 15,000 carnage
Accumulate 50,000 carnage
Accumulate 100,000 carnage
Accumulate 250,000 carnage
Accumulate 500,000 carnage
Accumulate 1.000,000 carnage
Kill 10 hiding players
Kill 25 hiding players
Kill 50 hiding players
Kill 100 hiding players
Get 10 stealth kills
Get 25 stealth kills
Get 50 stealth kills
Get 100 stealth kills
Kill 200 Nocs
Kill 500 Nocs
Kill 1000 Nocs
Kill 1500 Nocs
Kill 2500 Nocs
Win 10 Matches
Win 20 Matches
Win 50 Matches
Win 100 Matches