Going left offscreen here can get you stuck.

Entering this room from the bottom-left connection will trap you in a wall.

Otherwise, pretty cool game.

1. the spot at the top is where the demo ends. I should probably make a "thank you for playing" room.
2. I can fix that. 

3. any advice/things I should fix? thank you for pointing this out!

yep, happened to me too.
i went to that empty room to the left (with waterfall and 2 electrical things on the left/right)
and moved to the right room via dashing and got stuck in the same spot as the picture above