Whenever the controls switched to include numbers, they just didn't work (don't know if it's my keyboard or what). Also having checkpoints would have been nice so that you don't have to start all the way at the beginning after failing a backwards jump over lava (due to the forwards key being a number and thus unuseable)
Viewing post in Dungeon of surprising movement jam comments
Right. I have finally figured out what the problem was: My keyboard is not a qwerty, and normally when playing wasd-only games I switch my keyboard configuration to British so that they keys are in the right place. However, for this game I switched back to default so that I could actually find the letters I needed to press. Now my default keyboard only has numpad numbers; the numbers on the top bar can only be accessed by holding shift or having caps lock on. This doesn't work in your game: holding down shift or having caps lock on still doesn't make it register. And the number pad didn't work either, as you said.
So the solution I found to play the game was to constantly switch keyboard configuration: default when searching for a letter, then to British when I need a number. If I do this, the game works and I was actually able to finish it (to be fair not having to do backwards jumps makes it a lot easier)