Here is the full list of all 12 Military Madness: Nectaris achievements worth 200 gamerscore.
In the campaign, destroy a squad of POLARS with a squad of GRIZZLYS or vise-versa.
In the campaign, get a squad of EAGLES, FALCONS, or HUNTERS to Rank 8.
In the campaign, destroy a squad of RABBITS with a squad of LYNX.
In the campaign, destroy a loaded MULE squad.
In a Ranked Match, destroy an 8-troop strong unit in a single attack.
Win a Ranked Match by capturing an enemy base.
Win a Ranked Match by destroying all enemy squads or by your opponent surrendering.
Attain player level 30, unlocking all Commander Customization for Ranked Matches.
Attain player level 50.
Win a Ranked Match without selecting any Commander Customization.
Complete the normal campaign.
Complete the advanced campaign.