Thanks for the reply. Excellent comments.
I've been working on remedying a lot of the issues you've described (as they've also been experienced by other users). The comment about the boundary walls is quite useful, and I'll have to have a play around with it.
I actually had the double click to toggle movement on implemented before, but changed it under advice from another tester. Having tried both methods, I think I prefer the touch to move option more; allows flexibility without adding additional stress to having to push down. I might actually merge the options into one unified - click to start movement, but lift off finger completely to stop as the default. That way you don't accidentally trigger movement, but you don't have to grind your thumb into the touchpad. I'll see how user feedback goes.
The climbing is something I've been working hard on - both in conveying when you can climb and in communicating to users how to climb. The long and short of it is essentially that you can grab corners to pull yourself around. You can also grab shallow inclines (like the top of a table, or the top of the Huge Robot foot). Hopefully those changes will help improve how the climbing is perceived.
The slow walking locomotion is another issue I've been working hard on. The real challenge is that there are a variety of styles of walking in place, that a single default setting can't readily capture. So working on a detailed calibration system that will allow users to set it closer to their personal preference/style of moving right off the bat. For the people that it works for (currently), I've been told it's fantastic for all movement speeds though.
Hope to get an update in shortly.