So here I am, earned one more expansion on Desert Island in Sunflower Land. As you can see from the image here are requirements for next expansion.
3200 coins (have them)
250 wood
125 stone
15 iron
15 gold
30 crimstone
100 oil
60 gems (I have 91 right now)

Every expansion you have to collect a little bit more resources to advance. I think 100 oil will take me most time to collect.
This is expansion number 16 and it will cost me exactly 64.69 Flower tokens which is around USD $6.5
I also need level 58 for next expansion, but I'm almost there, I have 77807 / 118500 XP points.
For upgrading to Volcano Island, which is my goal, I need 10 more expansions and 200 oil.

Volcano Island is the place where I can produce Obsidian (rare and expensive material).
There are 4 seasons in Sunflower Land, each lasts for 7 days. During each season there are random cataclysmic events and today is Tornado effecting my farm and buildings (see image). You can buy protection for all events but I didn't have one for Tornado, so I'll have some losses.

Daily reset is in 17.00 local time, in 3 hours and that's when I'll be able to use my farm plots as usual.
If you want to join Sunflower Land follow this link.