Tango Fiesta

This achievement can be completed by replaying Stage 2-4 "Dutch Courage 4: Queen of Fear" in Story mode.

It can be completed with any character, but I would recommend Bionic Cop. He has the most health, and you will need as much as possible to survive this fight.

You can use any loadout you'd like, as you can't use any guns or grenades on the boss, only melee attacks with the R1 button are allowed. However, you can still kill the henchmen with bullets and grenades.

The Yatcha Queen boss has 3 forms.

1) In the first form she floats around and leaves a trail of pink slime that hurts you. This form lasts until you've taken off about one bar or 20% of her health

2) The second form begins after the second cutscene. She continues to float around the level, now leaving more slime and occasionally throwing pink slime bubbles that explode and cover an entire area with health-draining slime.

3) The third form begins after the third cutscene after the boss is taken down below 50% health. She begins jumping high in the air, leaving only a small circular shadow, then jumping back down to earth.

Tips

A) Like other levels, henchmen spawn infinitely. There are basically two types:

1) regular soldiers with low health
2) invisible "Predator"-like soldiers that fire purple bullets, have huge health pools and leave a puddle of green blood that hurts you when they die

Henchmen should largely be ignored unless you are low on health or ammo. They hardly do any damage to you and are little threat compared to the massive damage taken from the boss' pink slime. It's also very easy to inadvertently hit the boss with a stray grenade blast or spread from your shotgun, negating your run. I accidentally caught the boss with a grenade blast a few times and beat the level, but still had to replay it again since no achievement popped.

B) Ignore all the henchmen at the start of the level, charge right for the Yatcha Queen and start hammering away with your melee attack. You will have to get really close or even underneath her to do any damage, as the range of your melee attack is negligible.

C) Hammer away with melee attacks until you are down to 1/3 to 2/3 health, then retreat. It seems it's her pink slime on the ground that does the most damage to you, not so much touching the boss herself. However, the pink slime does damage to you VERY quickly. Keep a close eye on your health bar at all times. On my successful run, I retreated whenever my health bar was below 2/3, as it's sometimes hard to get the health kits to spawn predictably and I died too often if I hung around longer.

D) When you retreat, run as far away from the boss to the other side of the map as possible. Stay on the periphery. This map isn't procedurally generated and remains the same each time. It's very easy to inadvertently hit the boss with a stray bullet or grenade blast, ending your run. You can try melee attacking the henchmen as well if you'd like to stay safe but it isn't required. I personally don't find the melee attack useful against even the weakest enemies as it still takes several hits and you will be facing them when you are already low health. I preferred shotgunning individual henchmen in the face or well placed grenades for groups if the coast is clear. Pay attention to where the boss is with the yellow marker arrow when she is offscreen, especially when throwing grenades.

E) Getting health kits to spawn is really unreliable. Not every henchmen with a medkit bubble over his head will drop health when killed. This is another reason to retreat earlier when losing health meleeing the boss because sometimes you can't get one to drop no matter who you kill.

I found killing the "Captain" henchmen, who have the three golden chevrons ensigna over their heads dropped health and ammo kits most reliably upon death, but still not consistently. You can predict if a henchmen is going to drop health or not by how many shots it takes to kill them. Regular henchmen usually die with one shotgun blast, while the "Captains" who would go on to drop health would often take 3-5 direct point blank shotgun blasts to take down. The "Predator" type invisible enemies, who regularly have huge health pools, would similarly sometimes take entire 8-12 round shotgun clips to kill and drop health if they had the "Captain" emble over their head.

F) I kept getting a frustrating bug pretty much everywhere run where the third form of the boss who starts jumping high in the air would jump over the western wall of the map and not return to the playable area.

This only seems to happen during the third form of the boss during the floating and slamming back down. It occurred during my successful run, although the boss eventually returned to the field of play. It also occurs in the video I've linked below (which is not my own, Credit to FelipePsyco35 on YouTube).

I would estimate over 3/4 of the time on my playthroughs, the boss would get stuck out of bounds and force me to restart the level. Most of the time, the boss is actually stuck so far to the left that you can't even see her or her pink slime anymore, although you can still see the yellow indicator arrow and hear her audio prompts.

I didn't find any reliable to bring her back once she got stuck and I couldn't see her anymore. I tried killing the henchmen to make them respawn, hanging out in all 4 corners of the level, along with waiting 5-10 minutes continually killing or hiding from the henchmen to see if she would return, but the majority of the time she never did.

I observed that if she jumped the wall, but I could still initially see her or her pink slime, sometimes she would return to the playable field. But she has to return almost immediately if she is going to at all.

Once any amount of time has elapsed or she is no longer visible, it saves time just to reset and try again.

I would recommend trying to stay in the eastern half of the level as much as possible once after the third and last cutscene and she changes into her third jumping form. The boss only seems to get stuck outside the western border and never to the right. I can't guarantee this will stop the glitch, but it's your best hope. I'd also recommend trying to finish her off once she reaches the third form as fast as possible, as you'll have to restart anytime she gets stuck

G) Finally, here is a video link (not my video), of YouTuber FelipePsyco35 successfully completing the achievement with credit to them.