This if from the time where shift, ctrl and alt were the action buttons in action games… The norm for indie games currently is z, x, c … I wonder if this comes from Japanese homebrew games actually, at least that’s where I first personally encountered this scheme, in late-nineties Japanese PC games I got from Home of the Underdogs back in the day.
Anyhow, the shift and alt (and arrows) do feel ok to me, maybe because I’m used to them originally.