Originally Posted by Shiftie
Sticks like a bur - 20
Kill 15 enemies using sticky grenade.
To effectively get a kill with a sticky grenade you'll want to stick the grenade to your target, as they'll run away from the grenade otherwise. Multiple kills with one stuck grenade will count toward this achievement. Sneaking up on enemies to ensure you stick the grenade to them is a good tactic. Other than that, you should get this over your playthrough via sticky grenades that you pickup and/or purchase from merchants.
A few places you can get easy enemies in groups for this cheevo:
FRONTLINES - Right at the beginning of he level, the cart you were hiding beneath will stop just ahead of you in the tunnel. A superior officer will stand on the cart giving a speech to 4 sitting enemies. Get relatively close (since Artyom throws grenades like a little girl), cook the sticky for a little bit and toss it into the group. You should get 4-5 kills with this one.
Also, a little later in the level, when you get up to the top of the elevated rail line on the left-hand side (from your starting position), once you find the generator at the top of the steps, look to your right. There should be a white sheet hanging across an opening. Go around the sheet and there are two wounded but alive enemies lying on mattresses. They will do nothing as you toss a sticky grenade on them for 2 more kills.
OUTPOST - Again, right at the beginning of the level, run forward and once you clear the cave entrance, look to the right. There is a little shack for you to hide in. You'll hear some dialogue between the enemies about opening the airlock you just came through. After the dialogue a group of 6 enemies will pass by the shack and go into the tunnel you just exited.
They will gather in a group right by the airlock door. Again, get relatively close, cook the sticky for a bit and toss it into the crowd. Hopefully you'll get all 6.
If you can kill all the enemies I mentioned with stickies, you will have 13 of the 15 kills necessary. And it should pop the one for blowing up 10 enemies in the process - if you don't already have that one...