Hi! I am the designer of this game. Thank you very much for your feedback! Yes, the UI and communication could be a lot clearer, but we unfortunately didn't have time to implement everything.
The door you mentioned is one of the problems with the game's lacking communication.
That type of door closes after a certain amount of time. There is timer on the door while it's open that shows how much time you have before it closes, but nothing that explains what it is once it is already closed. Sorry about that.
I normally play with the arrow keys instead of WASD, so I didn't even consider that the X key would be a bad choice! I should've assigned another key to the dash as well, but thanks to you, I will know for next time.
But thank you for trying out our game and commenting on it! Much appreciated.