Here is the full list of all 25 Vicious Circle achievements.
Participate in an event.
Play 1 Round.
Get a kill on the Monster.
Play 25 Rounds.
Play 50 Rounds.
Play 100 Rounds.
Kill a mercenary as the monster.
Win a round.
Win 10 rounds.
Win 25 rounds.
Win 100 rounds.
Participate in 25 events.
Participate in 50 events
Participate in 100 events.
Participate in 250 events.
Kill a mercenary right after they use their escape ability.
Win a round after using an escape ability.
Collect 100 Nuggets.
Collect 500 Nuggets.
Collect 1000 Nuggets.
Collect 2500 Nuggets.
Collect 5000 Nuggets.
Equip a skin.
Equip a spray.
Equip an emote.