Here is the full list of all 25 Iron Soul achievements.
Escape from the main laboratory
Reach the CIC building
Stop the bot-mageddon before it’s too late
Survive the first round of madness
Become the Iron Soul
Find the secret item in laboratory (Chapter 1)
Just don’t die (Chapter 2)
Finish the level in less than 25 minutes (Chapter 3)
Score more than X bonus items (Chapter 4)
Hear all the hints during the mad puzzle (Chapter 5)
Find 3 Secret Items
Find 9 Secret Items
Find 15 Secret Items
Earn an A rating in Chapter 1
Earn an A rating in Chapter 2
Earn an A rating in Chapter 3
Earn an A rating in Chapter 4
Earn an A rating in Chapter 5
Finish chapter 1 with Expert Difficulty
Finish chapter 2 with Expert Difficulty
Finish chapter 3 with Expert Difficulty
Finish chapter 4 with Expert Difficulty
Finish chapter 5 with Expert Difficulty
Don’t die (If you can) during Crazy Level A
Don’t die (But you will!) during Crazy Level B