Thanks a lot for playing all the way through!
Speed has been an interesting one because a few people ended up treating it the same way. My idea was that, even if it doesn't directly help much in combat, moving faster means more runs and more coins over time. I also liked that it tended to make people invest quite a lot in the fighter before discovering the next branch.
Mend has a similar issue though, so I can definitely see how those two nodes can make parts of the tree a little too easy to miss. Something to think about!