When you start the game it says that you get all of the endings in less than 30 minutes. So no, you are not doing it wrong. It took me forever to get ending 1b though…
You should check out other O2A2 games then!
This was specifically made for this game jam where the concept is creating a game with no more than 1000 words, within 7 days and only one asset (1 sprite, 1 BG, 1 BGM/ambient, 1 SFX, 1 voice actor)