Ah, now this is a fun one. An anthology for some of DC's lesser known heroes is a great idea and I hope DC Presents sticks around.
The Challengers are such a classy, old-school concept. They're more a group of adventurers than they are a super-hero team, exploring ancient ruins, fighting living statues and recovering lost artifacts.
That's pretty much the gist of this issue, actually. The team check out their new home base on Challenger Mountain for awhile before jetting off to recover an ancient artifact buried in lost ruins which, of course, just happen to be guarded by living statues! But an old enemy may just drop in while they're out...
Challengers of the Unknown is done in what feels like a very classic style. Instead of using heavy close ups and superhero style action scenes this issue reads more like a 1950's serial adventure or an old issue of Fantastic Four. Instead of focusing on one or two individuals, most panels are devoted to group shots and the characters fill the upper half of the panel with back and forth dialogue. It makes things feel pretty cluttered at times but it's also kind of refreshing. A lot of modern superhero comics feel like they are divided into just two parts.
The part where characters talk to each(usually set in a base).
The part where characters punch each other(usually set in a street).
Using this style we get to see the Challengers travel, explore, and solve problems which should be the focus with a team of science adventurers.
The issue has weak spots of course. Like I said before many of the panels feel a little cramped and the characters could use some fleshing out. I found myself having serious trouble remembering which one was which and there are couple scenes where I'm almost sure the artist drew in some random extra person by mistake. Just a small box with each characters name thrown in somewhere on the first two pages would have been enough.
Overall, though, a good issue and a very fun read!