I like the enemies - basically one for each direction you can be hurt from - a good complete set. I agree with swoopie's idea of arrow keys for most comfortable single hand experience, but appreciate you wanting to experiment with 2 keys.
I'm sure that there are other ways 2 keys can be implemented with less friction, though, like maybe replace [gnd-Jump / air-Attack / air-Slow-fall] and [Turn] keys with [gnd-Jump / air-Turn] and [Attack / air-Fast-fall] keys. Maybe make slow-fall the default gravity (to make attack immediate) and automatically turn when you hit a wall. Just an idea - hard to say without having tried it, though.
Good to see you're still at it~