Bulletstorm

Definitely killed em all twice, but no achievement :( I did find out if you don't get it just go to the menu and hit continue and you'll be right next to the timer part.

As far as how it went for me, you have to kill every enemy that appears after the timer starts. In the video there are two guys who I had just killed and I'm not sure if they count or not. Apparently this achievement is a bit touchy as I've gotten multiple comments on the video saying that they've tried doing it how I did it, and it didn't unlock.

Just got it now, I just decided to try again after I turned my xbox off for a few hours and it worked.

FYI use the Thumper to kill ALL enemies in the room(s). It is far faster than the Boneduster.

Got it to unlock second try with the thumper, definitely the way to go

So as a follow up to above, it unlocked for me this morning after my unsuccessful attempts last night. So if you're having problems, and you're pretty sure you're doing it correctly, just turn your machine off for a while and come back to it.

That's it, KrakilinX. Thanks for that tip because I had problems with this achievement too but your tip was very usefull :)

I used the thumper to kill everyone in the room, even for the two that appear before the timer starts, and I did it 6 times. No achievement. I did so because I was too lazy to aim.

I finally decided to use the penetrator. First attempt, all killed, achievement unlocked.

So I don't know if this helps confirm anything or not but I just attempted this achievement about 5 times. Each time was with a combination of weapons and never exclusively with the Penetrator. My last run was with ONLY the Penetrator and it unlocked. Anyone else that is having trouble with this popping, try using only the penetrator and see if that helps.

Took several tries, but it finally worked using the Thumper.

Also, the achievement should pop right when the escape pod door closes.

@zombie Deej
You should just post this as your own guide. Mainly because you explain out how to get the achievement and it's effective. Some people, like me, are on old computers and I cannot watch youtube videos. They don't load.

The first time I went through the achievement didn't pop, so I restarted the last checkpoint and used the charged boneduster to kill all the enemies, and the achievement popped.

Check that all killed show you the skillshots points :)

Zombie Deej's comment refering to killing EIGHT specific enemies worked like a charm. Thank you :) I agree with Annie, you should write it as your own guide :)

thumper definitely didnt work for me

Would defiantly recommend holding off on killing the first two enemies, till after the clock starts, as pointed out above. Had no end of trouble with this one and my itchy trigger finger.

worked on my 8th go. used a mixture of penetrator and thumper (to kill the group of 4). i think the reason why it didn't pop before was due to the first enemy doesn't always die when shot with the penetrator. take your time and keep an eye out for the skillshot score to show on screen before proceeding to shoot the next enemy :)

Went through with the Penetrator and got it on my first attempt. For those of you who haven't got it or can't get it for some reason, fire more than one bullet if necessary. I did. :p

I found there were 7 enemies. There are 5 when you come around the corner, a single powered shotgun shot kills them all, and then there is one more in the next room and the last one trying to get on the escape pod. Pretty simple.

Zombie Deej is spot on. Wait till the timer starts before you kill anyone. I musta tried this 6 times with no achievement. Read his comment, waited for the timer to kill, and it popped right as I kicked the final enemy inside the escape pod.

After a few failed attempts I finally got it to pop Only after I killed the two at the top of the ramp where the timer starts. Used Thumper all the way. 2 at top of ramp. 5-6 in main room. 2 in room near pod. Popped as I kicked the turnout of the door

I'm also having problems with this achievement. I've tried multiple difficulties, after restarting my console, starting killing before the timer, after the timer, all kinds of combination's and no luck. I even tried my best to kill the guys before the barrel falls on them, but it's hard to do and I'd be amazed if they expect you to manage this (isn't done in the video). Another possible factor is whether it counts if Trishka gets one of the kills, but I'm pretty sure I've avoided that, plus I can't imagine the game tracks who actually kills each enemy for the achievement.

I didn't get it at first try, but then I reloaded the checkpoint (which puts you back at the last dropkit with the 2 guys at the door right before the counter starts), I was able to get it the 2nd time. Though I did it slightly differently the 2nd time, I used the Drill Penetrator for the first few guys, then the part where there are 5 guys shooting at you I used a pre-charged Boneduster which killed them all in 1 shot before the collapsing roof fell on them (don't know if that makes a diff), also, the very last 2 guys you kill just before you enter into the pod, WAIT 5 seconds before entering into pod (just to make sure their deaths are register before the cutscene) hope this helps.

Okay, here's what everyone is missing, and this sorely needs adding to the description. I JUST TRIED THIS ABOUT EIGHT TIMES IN A ROW, SKIPPING THE END SEQUENCE/CREDITS, RELOADING CHECKPOINT, ETC. This is solid fact, guaranteed, it will work:

Use your Penetrator. Do not instantly kill the soldier fleeing from you, chase him and wait for the timer to start. Once the timer starts, kill the TWO who are running from you, turn right and vault the obstruction, there are FOUR here, entering the escape pod room there is ONE soldier to your left. Finally, kill the ONE last soldier who is attempting to enter the pod. A total of EIGHT enemies if you include the two that it is possible to kill before the timer starts.

Important points:
~ DO NOT open fire until the timer has started. I'm not 100% that the first two count, but why risk it?
~ DO NOT use your thumper. Although it works wonders, you can easily interfere with the achievement using it.
~ The final enemy will trigger a SLO-MO scene. This is necessary for the achievement. Also necessary, he must not make it into the pod, even as a corpse.

Remember, the final cutscene and credits are skippable, and on the black screen where the General is talking, you can pause and Restart From Checkpoint if you've missed it.