Beautiful game! Nice experience, beautiful music and graphic design! 

The game play seems robust: simple and effective it gets the job done. Well done.
Please find here some suggestions to make the user experience even more enjoyable:

- I have noticed the timer to activate the interaction signal, well done. But probably sometimes the timer is not canceled when the character moves far away from 
  the interaction place. 
- Animations: The idle animation kicks in too quickly after changing walking direction, this disrupts a bit the 'underwater' experience (fluid movements).
  Probably more smoothing in the transition from walk to idle might help ( a longer transition or just an intermediate animation state).
- I would suggest to add a specific interaction icon for using and leaving a ladder
- The same for the hide icon, also probably the trigger for a small place where to hide the display / hiding of the 'hide here' icon could be smaller.