I wrote this as I played through, the so the notes will be in order of my experience, with some minor editing after I finished. Overall, you have a decent start here. I have a number of suggestions here based on what I think would be good, but this is your game, so do what works for you.
As a general rule, it is good to have some margins around text, between it and screen edges or borders. Your buttons with text, such as the Start button, could use with a bit of margin on the sides.
Clicking on "Touch Grass" gets an error of "Uncaught TypeError: Cannot read properties of null (reading 'currentTime') at SampleNode._pause".
Challenge Modes does not seem to do anything. It would be nice if the button was disabled, or displayed a message, if it is not yet ready.
I like that you have the option for disabling the fancy font for those who would prefer a simpler one. Similarly, having the Disable Clankers option for Robophobes is a nice accessibility feature.
While Escape is a common button for pausing, on web it can also be used to exit full screen. While this game does not currently offer fullscreen, I would recommend adding support for pressing "P" to pause as well as Escape. It would also be nice to offer fullscreen for those who prefer it.
I regularly saw errors about Tweens being started without Tweeners.
While I was testing how the rope worked and trying to attache them to the broken bridge I ended up on the edge, but not over it. I seemed to be stuck at the edge. I could not jump or move away. I clicked to restart the level, but it just reloaded and moved me back to where I had been and the ropes still placed. I then chose to return to the menu and restarted from there, and it restarted me on the rope level. It gave me the message about getting the rope again, even though I had the rope when I started. After that message the screen stayed a bit darker than it had been.
With the game controls primarily using the keyboard, it would be nice if the pause menu grabbed focus, instead of needing to use the mouse. I'd also recommend changing the "Exit" button to say "Resume", as I would think of Exit as exiting the game.
I think the falling rocks on the second level progresses the difficulty a bit too fast. Maybe the rope can help with it, but I wasn't really understanding how to use the rope, and was still figuring out the best way to move around. Every time I was starting to do well a rock would hit me and I was not able to recover. I think this level increases the difficulty enough without the falling rocks.
I did finally mange to cross the first gap. The sign on the other side had the end of the message covered over by part of the UI.
It felt like sometimes the hands would start moving in towards the body on their own. It also seemed like sometimes they did not reach as far. I think it may be tied to how things were moving, but did not fully understand the mechanics.
I stopped to write the above, and when I went back to the game and closed the message, I was unable to move the hands. I got hit by a rock and after that I could move them again.
I had enough trouble with the basic controls, and this new technique of one handed pulling, using these small grips, was where I stopped. I really think you need to add in a more gradual difficulty progression and more time to practice and build up skills for the player. A bit more explanation, and possibly showing how things work, would be good. I still don't understand how the rope is supposed to be used. Pressing R with the rope did not seem to do anything.
The game concept is interesting. Controlling each hand individually is challenging, but a good mechanic. The basic level design is a good start, but needs to be refined to introduce new players to the game at a better pace. You've probably played a lot and so are good at it, and it may seem easy, but you need to step back and design for someone new who is learning. You have a good start here.