Thanks for playing. I prefer W for jumping but I know some prefer Space. I think this is just a matter of adding adjustable keybinds. And yeah no pausing is implemented as of now. You can let go of a vertical rope without a jump by pressing down+left/right. The block should stay lowered, but it's possible that the lever got randomly hit by an enemy arrow when you passed by the area. It's not a one-time lever so the block just cycles up and down whenever the lever is activated.
As for the difficulty, I was curious how people would fare. The enemies can currently really go to town on your healthbar because there is no general invulnerability, so you can take contact damage (with a very brief window where it can re-hit you) and the damage from the attacks by two or more at the same time. And there's no way to heal yet, other than the crystal and the acorn which doesn't heal that much (did you find the acorn?). But there's a lot of finetuning that I can do in terms of how fast enemies can attack, right now they are quite fast, especially the knife goblins.
I'll try to play your game too but I'm soon leaving for a thing and I'm not sure yet how much time I'll have in the coming days.