j0frenzy said:
The one in Bioshock for playing through hard mode without Vita-Chambers. It wouldn't be so hard if not for Big Daddy fights. Still going to give it the old college try at some point soon.
That one actually gets a lot easier once you get about 1/3rd of the way into the game. I found it hard as hell at first (I'm not particularly good at any kind of FPS to be honest) but once you get your hands on the decent weapons and plasmids, stock up on armour piercing ammo and research them a few times, the Big Daddies just become a minor inconvenience. If you're still struggling with it, here's a few tips:
Preparing for the fight:
1) If you have any Proximity Mines, launch them all onto an explosive container, then pick the container up with Telekinesis. Initiate the fight by flinging it at the Big Daddy for huge damage.
2) If you encounter a Big Daddy without a Little Sister, Hypnotise it if you can. Then go hunt down a Big Daddy with a Little Sister.
The fight:
1) Use Insect Swarm as soon as you initiate the fight. The bugs will make the Daddy occasionally stop to flail around.
2) After you've used Insect Swarm, switch to Electro Bolt for the rest of the fight, re-applying Insect Swarm as necessary.
3) Electro Gel from the chemical thrower will effectively lock the Big Daddy in place as it damages them. A full tank on hard mode will sap away 1/4 of its health while it stands there shaking helplessly.
4) Electric Buck in the shotgun is the next thing you should switch to after the gel. It'll stop the Big Daddy in his tracks for a moment after each shot, and if you fire all four shots rapidly, you can knock off another large chunk of its health before the fight has even really started.
5) After this is done, pour all of your armour piercing ammo into it, or use the Launcher and grenades or rockets. If you don't have the Launcher upgrade that protects you from splash damage, avoid using the Launcher on Bouncers. If there's a decent amount of distance and cover between you and a Rosie, the crossbow can deal pretty exceptional damage too, but be wary of its long reload times.
Hope this helps you get the achievement!