Willem, yup, it's vertical. I didn't think the rules were that clear. I didn't even know what they were talking about. It's one of those things that you just start playing and see what happens.
You have the arrows down pat, you can put a card at either end of a row and it moves the row in the direction of the arrow on which you placed a card.
Lining up three of any card (twos, threes, kings) will have them removed from the playing field and you get points.
You can then place cards from the stock (the bottom bunch of cards in which the top one is visible and useable/playable) in any of those blank/open spots or again use the arrow on either side of the playing field.
If there is more than one of the same cards in a row (horizontal), and one is on the edge, so that it is: 2 A 8 9 2 J and you add a card, an Ace, to the right side, it will push the 2 off the field, BUT it is recycled into the stock at the bottom. Now your lineup look like this: A 8 9 2 J A
Now, whatever card you get next, you could add to either end, pushing one of the Aces off, and either way, that Ace is recycled too.
I do a lot of recycling of cards in the beginning, to get an idea where all the card ARE. I don't want to give up cards too early in the game.
Then there's the scoring, so that you'd want to set up groups of three in numerical order so that your group of Aces (low) are the first ones off. And your group of Kings are the last ones off.
That's not something I strive for, but it makes the game even more challenging if someone gets really good at setting up the groups of three.
You can kind of "cheat" a bit, and keep hitting "Replay" to bring up a new arrangement of cards, until you get one layout that has a horizontal group of three already there and they will be removed immediately. That will give you more space to play around with so you don't lose as many cards.
You can lose one of each of the ranks, and once the rank group is removed, that last card is "dead". It's only good for moving things around, and if you have a choice and HAVE to lose a card, that's the one(s) to bump off.
Have I made it more confusing? Or better? If one tip helps the most, it's probably the one to keep hitting Replay until you have a pre-made set that comes off the field right away.