aaru: Because your spies didn't start off from the back:
Place all spies to the last line (most distant from the enemy) and win the game.

martes: That's only 1 match with 5 games, where are the other 4 matches?

Total annihilation: Win a Reversi game by turning all your opponent's pieces to your own color.

martes: I think that achievment obly applies to normal Dice Chess. It does say "Kill your opponent's king" not "kill one of your opponent's kings"...

AbigailII: I think most of those are actually quite good and hard to get. Real achievments if you ask me

I'd just like to add one to the Checkers list (why isn't there a checkers achievment section?)
Power to the PeopleWin a game when your opponent had at least 2 queens before you got any (in checkers variants with queens, of course).

Pedro Martínez: Thanks for pointing it out to me. The portuguese translation is incomplete. I wonder if Fencer changed it after I translated it...?

AbigailII: Are you sure? I wouldn't expect it to be affected by that setting. After all, even with autopass, the word pass shows up on the notation...

FrancescoLR: He already created a prize... Look: Bonus Conqueror

aaru: Been there, done that
Now the triple assassin seems much harder, although there have been quite a few that made it as well - http://brainking.com/pt/Achievements?aid=157&submit=Submeter&p=1

EDIT: New sugestion for URL replacement - achievment names