I like the achievement system. Thanks HTC for implementing something of a to-do system in game.
Maybe it can be used to better implement other in-game systems. Also can it be used as a means of discouraging certain types of game-play (possibly via a name in lights type system or a website list for player achievements list?
Besiege a base : Kill 5 supply convoys inbound to a airbase.
Break the lines : Repair 15/45 structures at a airbase/town.
Strat-o-bomber : Destroy 5% of a country's start target.
Behind enemy lines : Kill a enemy country HQ.
Party player : Join a mission.
Party planner : Plan/Host a mission.
Chauffeur under fire : Deliver 10 troops for a successful base capture
A friend in need : Deliver 20 vehicle supplies to country vehicles.
Wingman : Earn 3 assists, on kills credited to a single player.
Join the band-wagon : Earn a kill/assist on which 2 or more players also landed an assist.
Hauler : Land a undamaged airplane with bombs/drop tanks still attached.
Party pooper : Kill 6 vehicles in rapid succession while in a bomber/attacker.
Sniper fire : Kill 5 aircraft while in a vehicle.
Down periscope: Kill a ship with a torpedo.
Milk-run : Capture a base with no enemy within 10k yards?
Cluck cluck cluck : Land with 0 kills after having an enemy in icon range while in a fighter.
Wham-bam : Loose all 3 bombers in formation within 2mins of killing a carrier.
Just a few off the top of my head.