Crypt of the NecroDancer

No Return Mode is a new game mode that was added with the Amplified DLC, and this achievement is an absolute pain in the ass. This mode causes the tile you were at the beat before the current one to turn red, and it will cause half of a heart of damage to you if you step on it. Essentially, you can never move to the tile you were just on without taking damage. There are no ways to avoid this damage without invincibility. What I mean is that only the ring of courage's kill dash invincibility and shields will protect you from the damage these tiles cause. As a result, you will need to relearn how to play with Cadence because many of your old techniques of dealing with enemies and stalling will not be possible anymore. Also, buffering of any kind will be even more important than it already is. This is because if you go into a corridor with only one way out, you will not be able to retrace your steps without wasting a beat. Whenever you move, you will either have to move forward, to the sides, or waste a beat somehow, otherwise you will take damage.

Some of the only advice I can give for the most part is to practice. This mode requires you to overwrite much of your muscle memory to even make it past Zone 1. Use equipment you are comfortable with, but weapons with a lunge, like the rapier, I would HIGHLY advise against using. If you lunge onto the space you were just on, you WILL take damage, so it is best to just use stationary weapons. Also, items like cookies are some of the best consumables because they give 6 buffer beats per stack, allowing for a lot more freedom of movement. Boots do not protect against the no-return tiles, so use whatever you prefer there as well. I would recommend stockpiling bombs if possible, though, because they make the Necrodancer fight much more manageable.

Easily the worst part of the achievement is the fight with the Necrodancer. Both Cadence and Dorian create red no-return tiles, and they will hurt either character, no matter who created them. For instance, if the two characters are in a formation where they are in a line with one space between them and you move either to the left or the right, one of the two characters will take damage every beat from the no-return tiles. This is such a bullshit design decision, but it is manageable if you come prepared for it. However, this makes the first phase of the fight extremely difficult because of the careful maneuvering required to hit all of the switches. Because of this, I would recommend just bombing the Necrodancer's stage to progress the fight. If you have enough bombs, you can just put them down until the Golden Lute drops on the ground. This will progress the fight to the second phase, which is much more doable the the first. You must still be wary of when one character moves and the other doesn't, though. The one that moved will still create a red tile even though the other didn't.

This achievement is pretty bullshit overall, but it is entirely achieveable. It just might require a lot of beating your head against the wall by attempting it over and over until you learn how to play this way.