How will early mainnet play out ?

While it's impossible to tell for sure, I expect the following when mainnet starts:

- Since about 9% of the total emission lands in town treasuries, early players will get a larger slice of that pie until more players sign up and start playing

- Building materials can be obtained at a high price from the game, and it will take a bit of time before players have set up substantial wood and stone producing industry and start undercutting the game's "last resort" wood/stone supply, so cost to build will start dropping after a delay

The first point favours early adopters, while the second one disfavours them. Regardless of which one ends up taking precedence, it seems safe to say that the people who have been playing on testnet to get to know the rules and get a feel for the game dynamics will be at a significant advantage, at least until newer players get the hang of it too.
   
If you decide to check it out before mainnet, here are are few things you'll want to have looked into as they are instrumental to an efficient play style:
   
- Farming timing and amount: grain and vegetables only grow when temperature is high enough, and crop damage happens when it drops too low, keeping on eye on season and temperature is a must if you specialize in farming.

- Ground potential maps: some locations are good sources of stone, others have more stable ground, or more fruitful land for farming, or grow different types of trees. You'll want to make sure you build your structures on land that lends itself well to your   buildings' types.

- Prestige: prestige accrues to players with the most impressive collection of gold coins, as well as most in game achievements. Four times a day, the twenty most prestigious players get a gold bonus on top of what income they earn through their buildings and other endeavours. Keeping your prestige up will be a great way to ensure money flows back to you.

- Inter building dynamics: this is probably the most complex part of the game mechanics: buildings influence each other: you get bonuses (or penalties) depending on which building types (whether your own or not) are close to your own buildings. You will learn how to place buildings in locations where bonuses are the best to maximize income. This can lead to impromptu player interactions: alliances where players cooperate to place each others' buildings in mutually advantageous locations, or conflict where players can even attempt to give other people's buildings certain penalties.

And there's much more! When you've checked out these, you may want to look into player created custom items, loans and mortgages, or creating your own city with a different map and 3D topography and its own specializations.