This is a personal, largely spoiler free (or spoiler-vague) review of The Undying custom scenario by Weyird for Arkham Horror the Card Game.
The Undying is a stand-alone side where investigators are up against a zombie horde, and have to stop the cultists resurrecting the dead before it's too late. The scenario has a great hook, and some clever mechanical designs, but fails to live up to the potential.
The Undying is a scenario who's set-up in an attempt to do a twist on Echoes of the Past - doom is placed on locations, and when investigators discover clues from those locations, they instead remove the doom and gain them as clues. This is accompanied by a lot of enemies - in 2 player, 8 enemies spawn as soon as this phase of the scenario begins! The entire scenario really comes down to if you can handle this initial rush. If you can, gathering the clues required to stave off the doom isn't hard. If you can't, you'll quickly be overwhelmed and unable to make progress. On top of all these, there are civilians to protect, who the zombies are after too.
In addition to how doom works, the design of the enemies is the other big mechanical twist, and it doesn't help the situation. Enemies have Shambler X, where if they're defeated, they become exhausted and get a resource token on them unless they've already have as many resource tokens on them as the Shamber X limit, in which case they're just discarded as normal. If you pull a Bless token during the fight, they get a resource token on them for free. While there are some bless tokens available in the scenario, they're pretty scarce - so if your party is packing bless, enemies become a lot easier. As is, the 3 health enemies with Shambler 1 are a major pain, likely taking 4 actions to take down unless you just run past them.
While the idea of having to fight off tough zombies sounds like it could be fun, but "just run past them" is where the real problem with the scenario lies. Because that's exactly what you can - and should - do. The scenario can be blitzed down rather easily, especially if you have any way of dealing damage from a range and can soak up some encounter cards and attacks of opportunity. Rather than interacting with the doom or the spawning zombies or the civilians, you can just run straight for the mission objectives - some squishy cultists - and defeat them. This does end up missing some of the story, but it's what the scenario seems to be encouraging you to do. And that's the big problem of the scenario that causes it to all fall apart - you can just choose to not interact with it, and go for a quick victory instead. You're far more likely to save people that way, too! If you do manage to get ahead on combat, getting more doom than is placed on locations isn't hard, meaning the only threat now comes from the encounter deck.
With a 19 XP party, I found The Undying to have a heavy amount of combat that I struggled to keep up with and still deal with doom, but not so much that I couldn't just rush past the enemies and go for the victory. There's a lot of mechanics here that would make the scenario significantly easier - bless tokens, the ability to deal damage at range, testless bonus damage, and the like.
The Undying has some neat ideas, and could still be fun if players choose to engage with its zombie survival mechanics over the actual accomplishments, but it feels a bit too easy to simply rush into victory or keep things at a steady state.
Rewards
XP Cost: 2
Potential XP Gain: 2 (locations) +2 (The Lich) +4 (villagers) +2 (purifying the cathedral) = 10 XP or 8 XP after costs
The scenario guide lists several rewards that are possible to obtain, none of which are included anywhere in the tabletop simulator version of the scenario.