As stated in the stretchgoal chapter there is a mix of different stretchgoals:
Stretchgoals available to all backers if the respective funding level is reached e.g. € 11.000.-
Stretchgoals related to a specific diorama. E.g. € 20.000.- This means, if you have finally selected a certain diorama at the end of the Kickstarter campaign the unlocked stretchgoals for THIS diorama are included as a bonus gift for the backers of this respective diorama. If you buy two dioramas all related and unlocked stretchgoals for THESE two dioramas will be included as a bonus gift.
Please keep in mind, that this campaign offers to you that you can do your final choice of your dioramas or animals at the end of the campaign. We hope to reach certain stretchgoals with your help. Based on this we possibly unlock a new kind of stretchgoal.
Stretchgoals which unlock Add-Ons. As an example the stretchgoal at € 23.000.-. This stretchgoal will make a new diorama available as a new option for your choice of diorama.
That means you can choose then 1 or 2 dioramas out of 3 available dioramas and you will receive THEIR RELATED unlocked bonus gifts.