Slitherine

Purple Heart is stated to be awarded if player accumulates 100 points of damage on a single land unit.

I got it after receiving total of 100 casualties on a Patrol Boat. Ship is certainly not a land unit but it may be regarded as a "ground" unit, or surface unit because it moves on a surface of an Earth. Also do note that there is some difference between casualties and damage in unit statistics tab so this can be confusing as well.

Air Ace Gold seems not to be working properly. Requires 15 aircrafts to be shot down with single unit and I have even more on one of my fighters (7 figthers, 12 tac bombers, 2 strat bomber according to stats).

Ghost Ship is kind of weird. It awards player for losing single unit for several times. Giving an achievement for using Reform function just once as part of teaching mechanism would be just fine.

The Ghostship achievement is inspired by this:

https://en.wikipedia.org/wiki/USS_Lexin ... e_Ghost.22

"word arrived during construction that the USS Lexington (CV-2) had been lost in the Battle of the Coral Sea. She was renamed while under construction to commemorate the earlier ship."

"The Japanese referred to Lexington as a "ghost" ship for her tendency to reappear after reportedly being sunk. ... There were rumors during the war that the ship was so badly damaged it had to be scuttled at one point, but a newly built aircraft carrier was immediately deployed with the same name, in an effort to demoralize the Japanese."