Here is the full list of all 21 Modern Combat Versus achievements.
Open 200 Multiplayer Victory Crates
Win 500 matches
Perform 5,000 kills
Reach the BRONZE LEAGUE
Reach the DIAMOND LEAGUE
Perform 2,000 kills
Open 50 Multiplayer Victory Crates
Reach the MASTER LEAGUE
Win 100 matches
Win 50 matches
Open 15 Multiplayer Victory Crates
Reach the PLATINUM LEAGUE
Perform 500 kills
Reach the GOLD LEAGUE
Reach the SILVER LEAGUE
Win 10 matches
Open 5 Multiplayer Victory Crates
Perform 100 kills
Win 3 matches
Perform 10 kills
Create or join a Clan