Oh, wait, it's not even out yet?! True, true — Reef has a U.S. retail release date of September 27, 2018, so while a few hundred people have picked up the game at Origins or Gen Con, most of this game's potential players have never seen a copy and quite possibly have never even heard about it. Many of us on BGG are plugged in to all that's hitting the market or being shown at conventions, but that's not how most people experience games, so let's give Reef a once over for all those just diving into the ocean.
Reef challenges you to build your own collection of coral, and while you are free to place the four colors of coral in whatever arrangement you like, you won't score any points unless you create patterns that match what's shown on the cards in your hand.
Each player starts with two cards, and each card shows two pieces of coral that you must place in your personal reef when you play the card and a scoring pattern that (almost always) is for colors other than what you just placed. On a turn, you either draft a new card from the display or play a card from your hand, then build and (possibly) score.
Points are sparse in the early turns because you'll typically have a particular arrangement on your board only one or two times. As the game progresses, though, you'll often draft a card or two that will score big as long you can find the right other cards to play ahead of it. Will you score those other cards as well? I hope so or else you might be wasting your time. Playing Reef is like riding a bicycle down a hill while simultaneously inflating the wheels. Every card is play is adding bits to your reef, but if you're not scoring points in the process, then you'll be dragging behind other players and one huge score near game's end won't help you catch others who have been keeping the momentum flowing constantly.
No one can mess with the bicycle you've built, but they can definitely snatch the pump from your hands. Watching the color flow on the cards drafted gives you an idea of what players will do on future turns, and sometimes it's worth your time to grab a middling card for you that someone else will transform into a rocket. If nothing else, you can still score the cards left in your hand when the game ends — which occurs when one color of coral has been exhausted — so if you would have scored that card only once anyway, now you'll still score it without having to expend a turn to do so.
The trick about this endgame scoring, however, is that if you would have scored something multiple times, you still score it only once, so you can't sit on things forever — which you wouldn't do anyway since you have a limit of four cards in hand. If you think the game is going to end, you need to get those cards out there to do the multi-scores, but then you'll be taking more coral from the pool and possibly hastening the end of the game in the process!
I've played Reef eight times now with all player counts (2-4) on both a pre-production copy and a review copy from Next Move, and the two-player game has been my favorite because you have more control over what the opponent can do via hate drafting, in addition to having a better handle on which colors are plentiful and which will likely score you nothing. In the image above, for example, you can see that I have exactly one green piece of coral — the one I started the game with — and all four cards are providing yellow coral while scoring other things. I feel you get weird situations like that more frequently in two-player games because fewer cards are taken overall, so you need to catch on to when such things are happening as early as possible in order to make the most of what you draft and what you let drift away...