The Components:
* 6 dice, 6 sided, each with sides: Wood, Wheat, Sheep, Ore, Gold, Brick
* Score Pad
* Rules insert

Play:
On your turn, roll the dice, hoping for one or more of the four combinations. You may reroll some or all of the dice in two successive rerolls. If you manage to obtain a scoring combination, and are allowed to build that item, you may score the points indicated in the item. If you failed to achieve any items you can score, you lose 2 points.

The key difference from feeling like Yahtzee is that you have a limitation that changes during play as to which combinations score. ALso, the more of a given type you've scored, the more they are worth.

The required resources are the norm for Catan:
Road: Brick and Wood. Always 1 point.
Knight: Sheep, Ore, and Wheat. progressive: 1,2,3,4,5, 6 points
Settlement: Wood, Wheat, Sheep, Brick. progressive: 3,4,5,7,9,11 points
City: 3 ore, 2 wheat. progressive: 7, 12, 20, 30 points

The lack of positioning choice is minor; it does detract slightly from the Catan feel, but is no more restrictive than Catan Kartenspiel.
Knights are not tied to road, but settlements and cities are.

Only certain combinations are possible:
1 road *
2 roads **
3 roads ****
1 Knight **
2 Knights ****
1 Knight and 1 Road ***
1 settlement **
1 Settlement and 1 Road ****
1 City ***

* is easy, **** is rather hard.

And you might not be able to score combinations due to not having roads to an unscored space.

Multiple Players:
Really, any number can play, but downtime is the issue. There is no player interaction, so downtime is the only real issue. There is no difference between playing solitaire and playing an opponent except for waiting for their turn, and kibbutzing.

Value for Money:
As a solitaire game, yes. As a component set for the official alternate version, yes. For multiple players, no. It's a nice time waster for 1 or 2, but more than that, and downtime becomes an issue.

The score pad, about 60 sheets, is double sided, and so you get two plays per sheet. It stands up well to erasure, and so reuse is possible.

A mistake?
Klaus Teuber, the designer, states on his website that he submitted two designs, and Kosmos published only one.

I feel Kosmos blew it.

Personally, I think BOTH should have been in the box; the alternate rules are posted on Herr Teuber's website, and actually have limited (yet still multiplayer solitaire) interaction, by virtue of it being a race to hit a specific score; further, it uses standard Settlers scoring.

Printing the second rules sheet, and an additional pad, probaby would have driven the cost from $12 to $15, but it would have been worth it.

Fun Factor:
It's enjoyable. It's not incredible, but it is a good adaptation for a solitaire Catan game.

Integration Factor:
One can easily integrate the dice into Settlers, replacing the normal process... but then one loses the robber except by army cards.

One can use settler's bits on the maps, but it's not a sure thing:
Settlers has 3 knights vs Dice's 6
Settlers has 15 roads vs Dice's 17
Settlers has 5 settlements vs Dice's 6
Both have 4 cities.

Variants:
It's easy enough to come up with variants. 3 are present on the site already.
I will add one, too:
Storage.
When you have rolled 3 identical resources, you may store 1 resource of that type; draw a circle outside the hexagon of that type. In a later turn, you may cross off that circle to add one resource of that type. Stored resources are worth no points, and storing does not prevent losing points for not having scored. (If you have settlers handy, ou may draw a resource card instead, which is more visually appealing.

Bottom Line: No player interaction, but still enjoyable for passing time. 6.5/10