I have played the game once and arrived at the conclusion that it is a great game, but that it would probably be better if the game was slightly longer. Maybe with twice as many cards. Since the game was created for an 18-card game design contest, my guess is that this limit in the number of cards is arbitrary and that the game has never been tested with more.
So I took a look at the distribution of resources on the cards, to think about what extra cards could be added to the mix.
The first thing I notice is that it is all extremely symmetric. All three resources are present in the same amounts, and distributed in the exact same way amongst the cards. In particular, Military doesn't play a particular role, with the only exception to this rule being the costs of the age III cards.
On every card there is exactly one wall, except on the starter cards which have 4 walls.
Number of cards: 6.
Each card is worth 1 prestige, on a corner.
Each card brings 2 of one resource and 1 of another resource, with all six possible combinations appearing exactly once, so each resource is present 6 times in total.
Each card costs one resource, and each resource appears as the cost of exactly two cards. The cost of a card is always the resource that is not present on the card.
Number of cards: 6.
Each card is worth 2 prestige, on adjacent edges.
Each card brings 3 of one resource and 1 of another resource, with all six different possible combinations appearing exactly once, so each resource is present 8 times in total.
Each card costs two identical resources, with two cards for each resource. The cost of a card is always in the resource that is not present on the card.
Number of cards: 3.
Each card is worth 3 prestige, on edges.
Each card is worth 4 identical resources, and costs 3 or 4 resources.
Computers and Space flight are symmetrical, with the first bringing 4 gold and costing 3 science, and the latter bringing 4 science and costing 3 gold.
Atomic bomb is the exception, bringing 4 Military but costing 2 Gold and 2 Science. In particular, no card costs Military in age III.
Thoughts about possible extra cards:
* Cards in age I with no prestige, but 4 resources instead of 3. Total 6 extra cards: 3 cards with distribution 2-1-1 and 3 cards with distribution 2-2.
* Cards in age II with only 1 prestige instead of 2, or no prestige at all, but more walls. This might also balance the complaints on the other thread that walls are not important enough compared to prestige and resources. Total 6 extra cards: 3 cards with 2 Walls and 1 Prestige, and 3 cards with 4 Walls and no Prestige. This would also break the symmetry just a little.
* A card in age III worth 4 Prestige (in the corners of the card) but no resources at all. This card would cost 4 or 5 resources, so it would be very good but also very hard to place.