There are many interesting ideas, and the (paid) planet mode may perhaps pay long-term gameplay.
But if you are not willing to pay up to 8 EUR per month, the game is forgotten after a week. In my view, the "solo mode" is only there to show the players what he missed when he does not subscribe to the Planet Offer.
This is achieved by the fact that the trading system for single player 1: 4 at a disadvantage (ie you pay four times as much for a resource, how do you get the sale). But since you need all resources and also in solo mode on almost all cards not all resources are available, you are forced to these conditions to act. This then is missing from a certain city size the money for further growth.
Public transport systems will obviously be only for subscribers of the Planet Offer.
Caution: for the solo mode is an Internet connection necessary because you have to log in !!!
In my view the game from the beginning has been programmed in as a paid online Abospiel. The solo mode is then like a perpetual paid demo version to see.
I have the "Limited Version" and has so far (excluding 5 unusable in solo mode Extra cards) see any advantages of this version.
I do it honestly sorry for my money and I can only warn everyone before the acquisition, which does not want to use the fee-based subscription.