Agreed with Neonivek and Othob Rithol : Achievements a-la 360 is (in general) plain evil. It forces you to stop playing the game it was supposed to be played so as to act in strange ways.
Wait what? You wouldnt be forced to complete any achievement goals. So what is this "it forces you" stuff?
I want the backburner: need 16 achievements...
Lets see...
Set a spy who's taunting on fire...don't see any spies...
Kill guys underwater with something other than the flamethrower...don't see anyone in the water...
Set guys on fire who then jump in the water...ok, I set him on fire...and...his medic heals him....he grabs a health pack...he dies...
Deal 1,000,000 damage with the flamethrower...(ok, it's really long term, I'm up to 172k)
Kill an enemy and have him kill you within 1 second of each other...
Kill someone with a taunt...
Kill someone right after they come out of a teleporter...
Have two enemy scouts one fire at the same time...when do you ever see two scouts at the same time?
Kill 6 people with your axe without dying...
Ignite 10 zoomed in snipers...when are you ever going to get that close?
Cause a dominated player to leave the server...what? REALLY?
Kill 3 people (any class) who are taunting...when was the last time you saw someone taunt in the middle of a battlefeild?
Kill a soldier with his own (reflected) crit rocket...you have any idea how hard it is to aim reflected projectiles? And the compression blast has a really short range.
That's thirteen acheivements that force a player to do something stupid or otherwise meet an impossible condition (or one that comes up ungodly rarely--friend of mine got the crit rocket one recently, legit). And I didn't even list the long term, but normally achievable achievements (kill 500/1000 people, destroy 50 buildings, etc.)
Here's a medic one:
Play a full round without killing any enemies, and score the highest on a team of 6 or more players.
That one's almost impossible to achieve on
an achievement server trying to give it to people!