Here is the full list of all 14 The Flock achievements.
Get victory in one round
Get victory in 10 rounds
Get victory in 25 rounds
Get victory while playing against a developer or a member of the Active Flock Players group
Picked up the light artifact
Became carrier 10 times
Became carrier 25 times
Played one round (tutorial counts!)
Played 10 rounds
Played 25 rounds
Light one flock on fire
Light 10 flocks on fire
Light 25 flocks on fire
Get burned by the light without dying, then become the carrier within 15 seconds