Farm 51 is very attractive strategy online game.
It's very funny and time consuming and it's free :)

I played this game many hours. I like this game and want to share some tips and trick with you. You main plot is money. As 50% of your cash in the game will be converted to tokens. Up to
50 000 tokens per game year. So our goal is to earn this sum as soon as possible.
You will have 1000$ at the start.
First, you will have to sources of income - chicken and crops.
Go to the general store in the town and choose most expensive crops.
Exclude cacao, sugarcane and orange from your choice. They are hard and long to grow.
Blueberries are optimum alternative. Plant one field on
blueberries. This is your first and main source of money for this time.
Your second source of money is animals. To raise animal you need water and food.
Buy one Water Trough and Feed(Quarter). Then buy as many
chickens as you can on the remaining sum. Chickens will produce
eggs, which you will sell.
Plant up to 3-4 blueberries fields as you have a money. Selling blueberries allow you to make next purchase.
Your next purchase is
Tractor. I know it is expensive -
10000$.
But it will help you to save the time for planting seeds and harvesting. Each tractor could work up to 4 fields or it will affect the speed of planting. So you need 3 tractors to work 10 fields of blueberries. This 10 fields will give you
25000$ each yield.
Next step is establish contact with aliens (Strange visitors). You will need
50000$ as minimum amount to build
Crop Circle and lure Strange Visitor.
But before you will do this, I suggest you to build
20 Silos to store the harvest and at least
4 Greenhouses to grow cacao and sugarcane.
Well I guess it's time to
try it!