Hi, I made a video playing the game. I found it overall really interesting to explore, with lots of possibilities (so many that I got a little lost). Really fun though getting lost and eventually discovering how things operate. Will the game have a coop version? I thought about a coop version when the player in the end falls into the hole with the skull (another player could throw a rope or something, I don't know). 
Congrats for the work!

You have only completed the training mode. After that, the story mode opens for you. Yes, having fallen into the pit, technically, you have completed the training, it ends there. I won't talk about other things, it will be a spoiler, but just start a new game and start the story mode.

You've still got like 30+ hours of game to play bro and coop is not likely coming except in maybe a mod when the game releases.

Bro didn't go in the story mode at all, but still enjoys the game.