So I really like it--the problem I ran into was that my keyboard doesn't have a key between shift and Z (on the third row, QWERTY layout). And my bottom row is Ctrl - Fn - Windows - Alt - Spacebar - Alt -Ctrl. So I had to kind of make up keys to go there.
I then ended up with a different problem, which was that when I tried to move to an adjacent ALT key, the...potatothing?...told me that ALT was "too far", because it thought I was pressing one of the other ALT keys.
Still, it's a very cool concept, and I'll probably return to it and fill in something other than alt keys for the bottom row and try it again.