Thanks for playing, and thanks for your comments!
QWAS was a recommendation from class; I couldn't tell if I found it awkward because I was already used to playing the prototype with WASD. In a final game of course we'd make that configurable although we're leaning mobile with this game.
Undocumented feature: The arrow keys also work (up toward top right etc) if that feels more comfortable.
Great suggestion on holding buttons! Thanks again.