Cuphead

If your achievement does not unlock when you defeat the queen, Tomahawk 5K suggests that you defeat the queen once again! That's what triggered the achievement to pop for them

This achievement is directly related to the following achievement, so this information and the video below are also going to benefit you in unlocking that achievement as well:

This achievement is unlocked after you beat each of the champions independently. As you complete boss levels and access new areas, you will see a ladder fall down from the sky, climb up it and you will fight an enemy inside the castle! But there are stipulations to all of these battles. You can only parry! So get that Y button ready (or whatever you mapped it to), because you are going to be using it a lot.

Here are my basic tips for each of the battles, the video below has more detailed information and can be used as a visual reference as well, so that is there for you to use should you feel the need.

Pawns
This fight isn't too intense. Especially if you are playing as Ms. Chalice as you don't even need to jump, just dash into any part of the Pawn's body to successfully parry them. Once all of the Pawns have lost their heads, you'll have completed this battle.

The Knight
This fight is probably the most annoying one for me, so I was glad it was only the second one! Now, my main tip is to make sure you stay close to the Knight. I know, sounds weird. But he is taunting you for a reason. If you back off and keep a wide distance between you and the Knight, he will perform an extremely cheap move that sends him across the screen extremely quick, attacking you with very little time to react.

Just stay close to him and parry whenever he has an opening.

The Bishop
I liked this fight a lot. Just ensure you are constantly moving from candle to candle, putting them out as soon as possible until the Bishop's head is once again pink (so you can parry it). Then parry him and rinse and repeat. Once the entire group of candles is lit up, that is the final phase of the fight and you'll need to put each of them out to get your last hit in on him.

The Rook
This fight is interesting. It's not exactly difficult, but it can get overwhelming very quickly. The basic breakdown of the fight is: Parry pink heads until they hit the Rook. My recommendation is to make sure you are going for safe parries, where you can land safely and then continue to juggle the head.

As you get more hits in on the Rook, more sparks come flying and more heads start popping out. Just be extremely careful, taking your time, making smart movements and watching the floor so you don't land on a spark coming at you.

The Queen
This fight is the most unique one in my opinion. You have 3 cannons that can only be fired one at a time, and they move around. Meaning you need to wait for the Queen to line-up with the cannon's attacks, and you need to avoid all of the incoming attacks from the queen at the same time. This fight is honestly not too hard, because if you are good with your aim on the cannons, you can take the Queen down pretty quick.

Hope this video and all of the information I have provided has been helpful to you!

Here is the video for both achievements:

If you drop any negative feedback, please PM me to inform me why. Constructive criticism will only make the information here better!