It's actually pretty simple. At least on paper. So, any New Game, any first playthrough for all users, starts with visiting the giraffe enclosure. Then you can choose to visit the penguin, gorilla, and wallaby enclosures. If you kill Sarah, you can only visit two of the enclosures listed. And any playthrough in which you save Sarah will let you visit four enclosures!
When you complete a New Game on any ending, you can start a New Game+. Instead of one of the animals listed above, a new one will be unlocked. I don't know if there is some sequence, but in each new playthrough I unlocked animals in the following order:
An incredible success for the studio's debut project.
In short, the company is aware of the problem and is solving it.
It will be an animated prequel series.
A free drone piloting simulator designed for schoolchildren and teachers. The game develops drone piloting skills in a safe virtual environment and is available on Steam.