For Shell Game, you have to shoot an overcharged Fusion Pistol shot through the bars by the 2x shield charger (this is the second one, by the way, the one you find before the room where you can see the target elevators, not the one underwater by where the fusion pistol spawns.). You can do this as long as you are pressed up against the bars, and it may take a few shots to get through, but you can do it if you’re positioned correctly. Also, only sprinting across from one elevator to another won’t work. I had to fire a couple grenades from my assault rifle to get the extra inches of recoil and make the jump.

Can I get achievements by selecting the related mission map from the menu?

For anyone struggling with Surf's Up - I found you need to be on the harder difficulties for the bob explosion to work.

Part 2:

Sleeping Beauty:
This actually unlocks at the end of level 22 (Kill Your Television) when you read the final terminal, but only after activating the last two mainframes. In short, complete chapter 7.

Keep the Oath:
Technically possible to miss, but easy to get by accident. Punch the circuit to the left of the exit door to unlock the achievement; reload your save afterward so you can finish the level without disabling the save terminal.

Mutual Incurrent Destruction Assurance:
As Kenzo said above, the best place to get this is level 17 (Begging for Mercy Makes Me Angry), where a MoAH will spawn with a couple regular Hunters and Enforcers in the sixth room, the one farthest to the northeast. I shot ten rockets in total before attempting to overcharge; any more and I ended up killing it by accident. Careful not to knock it into the plasma! With that many rockets, you can ensure you’ve got it weak enough to die to the explosion.

Thanks for the guide!

Hey, a few notes/corrections:

Vid Buoy:
This achievement unlocks when you read an exit terminal without spawning in the fusion pistol, regardless of whether you’ve hit the switches or not. Swim to the west, take the elevator up, then run south and read the terminal next to the southern switch. It's safe to go back and get the pistol after, and having the one from the level 3 secret won't invalidate the achievement.

The Citadel:
This actually unlocks at the end of level 10 (Eat It, Vid Boi) as soon as you set foot inside the final room of the level.

Surf’s Up:
I used this video as a guide of how to get up there and what path to follow. It took quite a few attempts, but eventually I got through.

Of note, you’re basically at the end of the level once you get there. Turn around, run to the west, activate the last airlock, and hang out there until you can get through, save, and end the level.

@Kenzo The Punished It's strange but on normal difficulty mother doesn't appear(((( Maybe On Total Carnage

@Kenzo The Punished thank you very much!!!

@suh123 If you still need mother of all hunters achievement,or anyone else

I think earliest you get this achievement is during the Begging for mercy level, where Durandal is in trouble or sumn and you help by breaking stuff. In the Southeast of the map you get your first checkpoint of the map, constantly save after each broken circuit, and eventually as you break more circuits, the game will disable first the health regen point and then checkpoint, when it disables checkpoint thats the time to get the mother of all hunters.

Leave the room and continue going right to the closest right door. Hunters and wizard looking guys will spawn along with mother of all, she wont leave the room but the rest will, bait them to leave and kill em, then, this is important, if you have shotgun(or any weapon will do) shoot her 5 times to weaken her and then hide again around corner and proceed to charge fusion pistol via right click, wait until 40-42~ beeps and then leave corner and come hug her

Just retried that section, you should reclassify keep the oath achievement, it IS missable since you can finish the game never hitting all 4 circuits, because as you start hitting those circuits, the lava immedietly starts rising, I swear 1-2 hit and its already rising and on my successfuly escape I only hit 3 because lava was literally above knee levels at that point and I thought I done everything xd.

>keep the oath is impossible to miss. But for some reason my game didnt register it xd