Marizipan is the only one that gives more happiness than the others - intended?
In the announcement, Gingerbread is the only one not needing two full level neighbors - I assume that is a typo then
Also it says
Once level 5 is reached, you will be able to choose among 4 different looks, with each one providing a particular advantage to your city.
This reads like level 5 is the max level with the choice and not level 6 - I think this would be better:
After level 5 is reached, for the next upgrade you will be able to choose among 4 different looks, with each one providing a particular advantage to your city.
I personally dislike that I do not know what I will get from the calendar doors. Although that is intended, it is crucial to at least know what could be behind it to make a proper strategy - go for all keys or go for daily specials - doing both will only be possible when spending huge amounts of diamonds.
Also, unless the currency is not majorly increased compared to last years, It will be impossible to get all keys with the free currency unless exceptionally lucky.