This hard playthrough is a lot easier than the one in Bioshock 1 if you ask me.
First of all you want to make sure that the Vita Chambers are enabled. That alone makes it a walk in the park.
Here some more useful advice:1.
You will find less ammunition and money so you will have to play somewhat conservative. Don't waste anything. 2.
Enemies do a lot more damage so don't Leroy Jenkins it.3.
Focus on Plasmids that immobilize enemies for a short period so you can land some easy hits.4.
Start researching enemies as soon as you find the camera for some sweet bonuses and additional Tonics.5.
Always make good use of available Security Devices.
Consider those few easy points and you shouldn't have too much trouble pulling this one off.
Once you reach Siren Alley you will have to decide for yourself if you want to continue like this and get the Trophy legit or if you want to take an easier route. Read on if easy sounds right in your ears...
In Siren Alley you'll have the first chance to buy the Scout Plasmid at the Gatherer's Gardens. Buy it for 40 ADAM. Now find a Gene Bank. Stand in front of the Gene Bank so you get the prompt to press
to use it. Select the Scout Plasmid you just purchased. You have to use Scout and almost immediately press
to use the Gene Bank. The right timing is a bit tricky. When you are in the Gene Bank menu select the Plasmids and pick any Plasmid to swap except
Scout. Swap the one you want with any other (or even with itself). Now press
to leave the Gene Bank. If you can see that Scout ghost in front of you now but
your left hand has the Plasmid active you just swapped (like Electrobolt ) you did it right. Just press
to get out of the activated Scout and you are hereby invincible
Like I said the timing is a bit tricky to get.However!
...the invincibility ends if you interact with any Little Sister directly (picking up, rescue, harvest) or at level transitions. If either of those two things occur...on accident or because you have to...just find another Gene Bank and do it again.