Originally Posted by Seddo
For the 'Kill 75 enemies while in the stealth mode of Overkill' achievement, will it unlock by firing your weapon and melee attacks or does it just have to be buy firing your weapon?.
Both types of kills count.
Yuyanami, add this to the guide. It'll help a lot of people. Found out that these places are the most accessible for these achievements.
Running Man 30
Start up the China level. Make sure you have the M134 with the most aggro it can get. Swap the weapon with your partner. Go up the stairs and put your partner in Aggressive Forward. When he gets to the point where there are guys let him kill 2. Put him in aggressive defend. You should get overkill in about 5 seconds or so. You'll be able to get 3-4 kills going up the hill. I manage 2-3 on average.
Next, you'll go down the hill. Again, let your partner kill 2 and get your overkill. Go back down the hill and you should manage 3 or 4 kills. I averaged about 4-6 kills per run this way. Not bad at all.
Note: Sometimes this doesn't work because your partner AI melees the troops and acts retarded. He only acted retarded 2 out of 25 or so times for me.
Same thing as the China mission except this time get the Ak-47 with full Aggro. Kill 2 people and wait for overkill to kick in. I got about 8-10 kills in overkill mode going up and down the stairs all the time.
Should take you 1 hour to get both achievements if you've played through the game once or twice. About 1 hour 45 minutes if you haven't gotten any overkill kills yet.
Big Boom! Big Bada Boom! 20
Start up the Aircraft carrier mission. Once you get inside the aircraft carrier for the first time, you'll see a Riot Shield up against the wall. Take out your Stinger or RPG (Stinger works best) and go out the door. In one stinger shot you should be able to get 6 kills or so. The checkpoint is right there so it's very accessible.
Starting a Riot 30
Same as the above. Use the Aircraft Carrier Mission.