Here is the full list of all 12 RISK Factions achievements.
Achieve 10 super overkills
Kill 100 human, cat, robot, yeti and zombie units
Control 5 capitals
Earn 10 stars and trade them for 30 troops
Complete the human, cat, robot, yeti and zombie campaigns
Be the first to get an objective in a game
Defend a minimum of 5 attackers with 1 defender
Defeat someone in online multiplayer who has earned the Man Up! achievement
Play 5 games online
Win a 5 player online ranked Command Room game
Win a game on each map
Win 10 online ranked games