I tried the sandbox and this is overall quite fun. I like the fact the game is technical, i.e. you have to consider the distance carefully before taking jumps. But I like even more the fact that you basically made a climbing puzzle in which figuring out your way up is half the fun.
I have some constructive criticism however. In my experience at least, when climbing, switching from one side to another worked less than half the time. It felt very inconsistent. Also, there were a few times where I barely missed a jump, and I wasn't sure if I wasn't timing my jump properly or I just wasn't supposed to make that jump, and so the game didn't convey this information well.
Looking forward to seeing the game improve!
Could you add me to your Discord server?