It's been 6 days, more hints needed.
Hello kalirion & everyone else!
I am sorry for the long radio silence, it was my fault to not post another (few) picture(s).
The past two weeks were full of an excessive amount of extra hours at work that kept me too busy and too tired.
Thank you for continuing the guessing game in the meantime. And yes, kalirion, my screenshot was indeed from the ending of "Lumo" after having collected all rubber ducks during the game.