Thanks to you both for the great suggestions!
I ran a bit of a test campaign yesterday with two players. They really enjoyed playing plasmoids (named Jelly and Jellamy) and were very creative with the uses of pseudopods and slipping through spaces. If you’re interested to hear the deets, read on 
I set them up as muscle on a Dohwar trading vessel en route to the Rock of Braal. Jelly is a rogue and Jellamy is a bit of a custom class I found online, a “trick shot” bard, both level 6. Anyhow, they failed to perceive the spelljammer wasp ship in time to evade it, and so their ship was boarded by space pirates dressed like clowns who immediately went for their spelljammer helm. As they tried to deal with these pirates (Bandit stat block), a crying little girl appeared on their deck, claiming to be trying to escape the pirates. Not trusting the little girl one bit, Jellamy cast sleep on her, but it failed, and the little girl revealed her true identity, a ghoulish space clown with black bloody sockets where her eyes should have been. The PCs were able to take out 3 of the 4 pirates, but it took both of them to defeat the space clown, Giselle, and the 4th pirate escaped with their spelljamming helm. I was particularly glad to have Jellamy subjected to the side effect of the space clown ray gun (similar to Tasha’s Hideous laughter). Super fun battle.
So, their ship, the Allegro, was adrift for 3 days until it literally crashed into the docks of a dwarvish asteroid mine (Moradin’s Mine). The dwarves confiscated their cargo (about 3000gp worth of goods) and put the Dohwar to work in the mines as further payment for the damage. The PCs are able to strike a deal with Moradin to greatly reduce what they owe and avoid enslavement. Basically, dwarves have been going missing from the mine lately, and Moradin is concerned about labor union activity. The mine is a very lucrative one for Moradin, since it contains the crystal components required to make spelljamming helms. The missing miners is a major concern for him, since it is resulting in a loss of production in and of itself, and if it is due to labor union activity, Moradin wants to squash it right away.
To set up the delve I actually used the Perilous Wilds dungeon generation tool (my favorite GM tool!). I had them roll a d12, and right off the bat it was a danger! Originally, in my head I thought I would set them against a minor trap. Jellamy avoided falling when part of a bridge crumbled, and my thought was to have them roll again (wanting them to continue exploring). Jelly was particularly interested in the room, however, and was really doing a great job “discerning realities.” Even though we were playing DnD, I’ve played a fair amount of Dungeon World with these two players, so they are skilled at being a part of the narrative. Jellamy cast dancing lights up at the ceiling of the cavern, and soon we could see that the room was like one giant geode, lined with large cuboidal crystal stacks with the floor about 30 feet below. Jelly noticed a dwarf spying on them from amid the crystal forest below and climbed down quickly to investigate (level 6 thief). He came upon two dwarves conferring in a bit of a clearing, but he found their behavior strange, since they weren’t really speaking so much as standing there staring intently at one another, as if communicating by other means.
Jellamy took longer to climb down, and she decided to sneak around and try to observe from another vantage point. While she was observing the dwarves, a third was able to get the drop on her, smashing her against one of the crystals with great force. Jellamy took a lot of damage that battle, getting down to just 10 health. Jelly was able to sneak attack and one-shot one of the two dwarves, who melted into a grey blob of flesh and bones as he died. Jellamy grappled with her opponent using the pseudopod rules for plasmoids and was able to blast her with her pistol and then finish her off with a short sword. Next turn she cast major image as a distraction, which succeeded, and Jelly polished off the last dwarf with a sneak attack empowered rapier strike!
We had to end the session at that point, so the players did not have a chance (yet) to inspect the blobby remains of the three dwarves. These are not actually dwarves but psurlon ringers who have consumed dwarves and transformed. The psurlons secretly invaded the mine months ago to engage in one of their feasting rituals. Future encounters will include more psurlon ringers as well as, once I build up some more tension by causing most of the inhabitants of the mine to go missing, normal psurlons (which are more difficult enemies). Eventually, they will have to take out the psurlon leader, or perhaps try to escape the mines on another vessel (or by stealing a spelljammer helm).
For both combats I used the idea from the youtube link posted above. I don’t know if it is because the players had played DW with me before or what, but it pretty much played out like DW combat with little intrusion by the DnD mechanics. The addition of using a timer really added pressure for the players to think on their toes, and no one had to wait for someone else’s turn. Narrating what happened based on the results of the rolls was really fun, especially since both players kept rolling so badly!
