The app has a quickplay mode, where you can just jump into the minigames if you want (steering the boat, hooking crab pots, rescuing a man overboard, or sorting crabs on the table), but the real pleasure is the campaign mode, where you can actually build a boat and crew out of the cast of Deadliest Catch, and then make your own way out into the Bering Sea to try and catch Alaskan crab. Mixing up the minigames is a lot of fun -- just like the real sailors, you lay down pots, check them as they come up, and hope that you hit the crab motherload. The app faithfully recreates the show's feel of going out on the deadly ocean and searching the depths for that big pile of crab that means you'll come home with some cash.
The only drawback is that at US$3.99, the app is expensive, especially for a licensed title. Not that $4 is expensive for a quality game (if you like the show, it's worth picking up), but for something that could itself serve as an ad for Discovery Channel, that price is a little steep for the potential audience. The good news is that there are no ads in the app itself (except for some links to both Discovery content and developer Hands-On Mobile in the menu), and it runs surprisingly smoothly, even on my old 1G iPhone. If you follow the Cornelia Marie and the Northwestern like I do, grab it right now and go crabbin'! Everybody else can wait for the eventual price drop.