Live Forever Achievement
The main things you need to get this achievement are patience and a good understanding of each boss fight so you can down them with no risk of a death. Beyond that the most dangerous things are spikes and instant death pits + the elevator in stage 2 since it has plenty of spikes and enemies to knock you into them. I suggest practicing the elevator before attempting this achievement.
Don’t Touch The Paint Achievement
This section takes quite a bit of practice. For most of the first section you will want to just mash fire as you are going then towards the end use a charged shot on both the last set of enemies + the 2 floating ninja star traps. After that make sure you work in charge shots everywhere you can on the second section especially for the enemies with the shields.
Born Ready Achievement
This is the achievement that forces you to master the game in order to get it. By the time you get this achievement you will know every boss pattern and you will have to work out a safe path through every section since your hit points are very low. This also is probably the mode where you will realize that extra jumps after shadow dashes only are available when you actually have SP so keep that in mind. The only real advice for this achievement is to remain vigilant, have patience, and play strategically instead of rushing haphazardly to your doom.
Fast As Lightning Achievement
Sub 3 hours seems like a big task after your first play through but if you managed to complete Born ready you will be able to fly through the game like a true cyber ninja.