Hi there!
As the full game is still under heavy development, I can't yet give an accurate estimate of the final play time, but I'm hoping it should last around 3 hours. Although don't hold me to that! We shall both find out together.
[ECHOSTASIS] will be a paid game. I don't yet have any information about the price of the final game, but it will be somewhere between €10-€20.
Thanks for your lovely comment!