I'm voting for Dan
Attack Power
Going off what is stated above Snatcher is 56 times stronger which means he can easily one shot Dan. However, Dan has Low-Godly Regenerationn which means he'll regenerate any damage Snatcher does to him. Dan does not need Mid-Godly Regenerationn because Snatcher is not destroying his soul or mind, just his ectoplasmic body. To destroy or incapacitate Dan, Snatcher needs to either destroy his soul which seems out since Snatcher Soul Manipulation is just removing the soul and Dan has resistance to soul attacks. Or Snatcher has to destroy Dan's core beyond it's Regenerationn but Dan's central core is his consciousness/mind and I don't see Mind Manipulation or Snatcher's page and Dan resists mind attacks so Snatcher can not put Dan down.
While Dan is outmatched in terms of raw power, his ectoplasmic attacks effect the mind and soul which Snatcher has no resistance to so he don't need raw strength to harm him.
Speed
Speed's Equalized so it's a non factor.
Abilities
Both have Non-Physical Interaction so their Non-Corporeal/Intangible powers aren't useful. They are bloodlusted so Snatcher's Social Influencing is out. Dan can sense Snatcher thanks to Ghost Sense so stealth is out but Snatcher's Extrasensory Perception and Enhance Senses doesn't say anything about seeing invisible beings. I'm sure he can sense Dan but seeing him when he's invisible is a different story.
Snatcher's Soul and Death Manipulation are out because Dan resists soul stuff and ghosts are treated as undead beings so he can't inflict death on him. Snatcher only seems to make a single duplicate while Dan can make at least 3 extra clones and over a dozen scaling off of Vlad so he has the numbers game on his side. Both have teleportation and while Snatcher's brings them to a void, Dan can easily open a portal to escape. Looking at Snatcher's battle with Hat Kid, he never teleported her into his attacks even though he was clearly trying to kill her so I don't see him doing that to Dan.
Dan's Regenerationn is better and his Ghostly Wail negates up to Low-Godly. Power Nullification won't help on Dan since he resists power null. Both have telekinesis but Dan has higher lifting strength while Snatchers is unknown so Dan can easily wave his hand an hold Snatcher in place. Snatcher has danmaku and giant piller explosions but from watching his boss battle, Dan can easily avoid or teleport away with not much issue. Yes, Snatcher could use teleportation to put him in a spot but he didn't do that against Hat Kid from what I saw.
Pain Manipulation is fine but he only seemed to do that when you cheat. Even during his boss fight he didn't use it, and I'm not saying he won't, it's possible but that's like me saying Dan will abuse Time Travel if something is about to go wrong and he needs a do over. Also, as I stated before, Dan was caused continues pain by the Specter Deflector and in seconds later after being hit, it had no effect on him anymore so I'm sure Dan will overcome this as well. Dan also has Possession which he can get off by sending multiple duplicates to distract and attempt it.
They both have a few other abilities like element manipulation and what not but nothing note worthy from what I can see. I'd like to point out that Dan will possible be getting
Reactive Power Level from this thread.
https://vsbattles.com/vsbattles/4161487
Stamina
I think Dan has more stamina honestly. Yes, Snatcher could spam of lots of attacks in his battle but so could Dan. Danny, who has a stamina limit could use his abilities and chase ghosts for hours non stop and fodder ghosts have shown to hold their powers for days with no issue. Dan being above Danny and other ghosts means he could keep going for days without issue so he takes stamina.
Range
When it comes to their standard abilities Dan has much better range with blasts and AoE with Ghostly Wail. Snatcher has higher range with his interdimensional though. Not much of an advantage for either side given how they fight.
Vote
As I stated above, I'm voting for Dan. Yes, Snatcher is more powerful and has a wide array of abilities but most of them aren't too useful or get stopped by Dan's resistances. Dan's Regenerationn abilities are high and will allow him to survive Snatcher's assault along with teleportation and shields. Telekinesis can hold Snatcher still and while that won't stop all of Snatcher's abilities, he'll be cought off guard. As I said before, Dan's ectoplasmic attacks ignore durability so he doesn't need raw AP to harm Snatcher.
I will admit that Snatcher attacks have some good Area of Effect but they aren't impossible to dodge. A sound plan would be to do as EMagoIorSouI said and start with thought based pain manipulation + danmaku and if Dan tries to escape just teleport him into the explosions. However, I don't see Snatcher doing this even while bloodlusted he seem to spam explosions, duplication + darkness in his boss battle against Hat Kid.
Let's say he does spam the method EMagolorSoul said. Dan will just regenerate and he has enough stamina to keep this up for a long time and will likely outlast Snatcher. Dan in my view of things has more going for him that's actually effective.
Note: I did not see all of Snatcher's fights since I have never played A Hat in Time. If anyone has anything important about Snatcher that I missed, let me know.