Hi, first of all, thank you for playing the game and for your kind words. We really appreciate it! We’re currently working on adding more content and fixing as many bugs as we can.
Regarding the saving issue: during your gameplay, did you reset the island by clicking the “Set sail for a new island” button in the top-left corner? The game only saves progress when you enter and exit the meta screen. In other words, the current island itself is not saved, only the meta progress (such as your skill tree and unlocked fossils).
If you did reset the island and your progress was still lost, then this is indeed a bug on our side and something we’ll need to investigate and fix.
Once again, thank you for reaching out and for playing the game!