First Strike is Games Workshop's attempt to introduce more people to the Warhammer 40k tabletop game with an inexpensive and attractive starter set, and I think they've done an overall decent job with it. Inside the box, you get a playmat, some dice, a mini rulebook, a book with more information on the 40k universe and hobby, some data cards, and of course the models.
You get 3 Primaris Rievers, 3 Primaris Intercessors, 3 plague marines, and 6 poxwalkers. The models are all of the snap-together, easy-to-build, variety, but you should probably still have some modeling glue on hand, just in case. You'll also need a pair of snips to cleanly get the models off the sprues. The models come in blue and green colored plastic, but of course you still can paint them if you want.
The models look very nice and assemble pretty easily. They have a lot of detail to them and they all are different in appearance from what is included in the Dark Imperium starter set, so this is a good way to add some variety to that set. The plague marines in particular look super detailed and nasty, in a good way.
The other major plus of this set are the two mini books that it includes. They are both nicely bound and have a lot of useful information. Having the core ruleset in a nice little book is particularly neat. The data cards are cool too; they're sort of like the Age of Sigmar warscrolls and they come on nice thick paper.
Unfortunately the other components aren't quite as high quality. The dice are rather small and feel cheap in the hand, and the playmat, while it's nicely printed, is made of pretty thin paper. It's a little disappointing that GW went cheap with these components. I know this is a bargain starter set, but it wouldn't kill them to throw in some decent dice.
Overall, this set is kind of like a scaled back, casual version of version of the Dark Imperium box. You have everything you need to play a small, quick game of WH 40k with a friend, and it's not a bad starting point for someone curious about the hobby, particularly if you're not sure about painting your models. I could see this being a good set for kids that are interested in tabletop gaming, or something that you keep with your other board games for a casual game here and there.
If, however, you're a longtime fan of the 40k universe and you're serious about getting into the tabletop game, I think you're much better off saving up some more money and getting the Dark Imperium set. You'll get the full rulebook, bigger armies, and the full experience of gluing and painting your models.
Warhammer 40,000: First Strike Miniatures, rules, scenery and painting information in one box - the perfect starter set to begin a journey into Warhammer 40,000. This awesome value boxed set includes: 3 Space Marine Primaris Intercessors (easy to build) 3 Space Marine Primaris Reivers (easy to build) 3 Plague Marines (easy to build) 6 Poxwalkers Read This First 56 page book - gives the reader a glimpse at the Warhammer 40,000 background, galaxy and factions, contains a step-by-step painting guide for every miniature, and includes 4 training missions. Core Rules 24 page book - includes the core rules of Warhammer 40,000, how to set up games, a guide to using datasheets and the Only War mission. Also includes datasheet cards for every miniature, dice, a range ruler, an Ultramarines' decal sheet, a 2'x2' double-sided gaming mat and a reversible tray, used as a scenery piece, allowing you to get started straight away. Miniatures require assembly and are supplied unpainted. Paints, tools & supplies sold separately. - Warhammer 40,000: First Strike