Kevin B. Smith
Is this good for adults?
Based on a few plays, with just myself or only other adults, I think it's fine to play without kids around. I find it very thematic, especially the narrative arc with the radio and then the scramble to the rescue van.
I am only interested in it as a pure co-op, so I have played 2-player, and a houserule that if either player dies, the game ends immediately. (Instead of that player becoming a zombie and working against the other player, as per the official rules.)
The complexity of Dead Panic is higher than Castle Panic, but perhaps slightly lower than Castle Panic with the Wizards Tower expansion. Based on watching videos of Star Trek Panic, I would say that STP and DP look comparably complex.
As for winning Dead Panic--I have found it quite challenging. I am baffled by others who have posted on BGG that they find it far to easy to win. Maybe I'm terrible at the game, or maybe I'm missing a rule, or the scaling by player count is wonky. but for now I'm clinging to the belief that those who win easily might be getting some important rule wrong.
I think scaling may be a little wonky.
I've played a few games 2-player with my wife, and we get slaughtered.
Once, maybe twice, we played with two characters each, and we did pretty well.