Never had the chance to play Dust Palace (thanks, Activision), nor the assault on the Black Garden. Is that one any good?
It's a lot of fun if you're strong enough. I died once and managed to pull my teammates' asses out of the line of fire a couple of times with a well-placed bubble. Really felt like a useful part of the team.
As Ghaleon said, I was simply amazed at the amount of enemies they were throwing at you. Those goddamn Thralls just kept coming.
Dust Palace is almost step for step the "Buried City" mission that is available to you.
You enter the building and get to the first door. You have to kill a Major Psion to open the door.
You go upstairs to the area with the huge window and curved stairs. You have to kill a Major Psion to open the door here, too.
You get to the top of the tower where you find that Rasputin link in the mission, and you kill another Major Psion to open the last door.
This leads you out to a small landing balcony where you take on the bosses. I used to hate this fight, but now it's one of my favorites, just because the bosses aren't sponges like so many others.
Undying Mind is very unique. It feels like a stress test. You start at the chamber with the Heart and work your way backwards thru the Black Garden mission. But really, you only stop and fight at like 2 different areas.
The big open space where you activate the eye of the gate lord is basically the "Kill 3 waves of Vex" part. But they put a crazy amount of Vex down there.
Once you climb that hill/starcase you get to a digital wall that you can't walk through, but there is a Cyclops on the other side of it. This part is interesting because the game will keep throwing Major Minotaurs and Goblins at you non-stop until you kill the cyclops, and even then a decent amount of time post-mortem. After that, you just pretty much run to the boss room and fight him.
The room is very square and the boss just strafe's from the top center to bottom center back and forth, and the adds are super predictable with where they come from.
It's not a bad strike, but it certainly isn't one of the more memorable ones.