Really cool mechanic, would feel a bit more satisfying if the bullet travelled a bit faster so you could pull off some slicker trap moves. With some audio and a bit more speed this could get really exciting.
I'd love to have the option to jump with W, it might just be me but I find it hard to use A and D for movement, Space and Shift for mobility as well as the mouse for attacking. If all the movement is on WASD it just makes it much easier to manage everything.
Good effort though, would love to see you expand on this concept!