Ghost of a Chance To unlock invisible enemy mode you must beat the story with Jill and Chris on the save file (meaning when beating the game load the game then choose the next character on the same load) and then Hard MUST be finished too. Either that or beating it on Real Survival will unlock invisible enemy mode. Once you do either of those 2 requirements it will be under Real survival mode when loading the file.
When you start up the Invisible enemy mode you can do easy to make this the easiest. If you did it on Hard then it would possibly even be harder than True Survival mode (possibly).
So to start you off I want to say don't make the mistake I did, I attempted Invisible Enemy mode, only using my knife(CQC FTW achievement), under 3 hours (which can work if you are only using a knife), AND my biggest mistake, without saving (Ink is for squids). I got past what I thought was the hardest part having invisible enemies (LISA) to underestimate the Fuel capsule that blew up in my face right in front of where I had to insert it 10 minutes away from finishing the game.
So make sure when you do this achievement, to not mix it with the wrong achievements.
The video I used is in this solution:
The CQC FTW achievement in Resident Evil worth 145 pointsFinish the game using only your knife (no lighter, Defensive Items, and stomping zombie heads). The basic idea is to just run past everything. The bosses and Crimson head put up quite the fight not being able to see them, or use guns for that matter, so this is why I recommend at least having guns or being able to save while doing this.
If you want to use guns the video below is for you done by Shirrako and does it right under 2 hours giving you plenty of breathing space to make mistakes or watch some of the video first.
Be careful: When you pause your game it does not stop the in-game time, when you start a speed-run you cannot pause the game constantly and expect a good time. You can either play the game while watching the video (which is what I did) or you can save, quit, watch video, start up again and play until you get to another save spot with what you watched.
A good tip to know is that there is always hints or ways to see the invisible enemies, The bosses are the ones you need to really pay attention, everything else, you can basically just run past (except the 1 crimson head).
Any questions or concerns? Comment or message me, good luck and have fun everyone