Gameplay Test

Trying out some stuff for a potential new game, and I wanted to try and get people's feedback on what feels best for the controls so far. Really basic, just jump and shoot at this point. Hold down Left Shift to run, Space Bar to jump, "B" to shoot, and Right Shift to spawn another enemy. 

The ground does run out after a while in either direction, so please don't go too far away. Each of the eight variables can be changed up/down with the following keys:
Walk Speed (Q/A)
Run Speed (W/S)
Jump Strength (E/D)
Gravity (R/F) (Affects gravity when you are descending only)
Stop Speed (T/G) (deceleration speed)
Shot Delay (Y/H) (How long between basic pistol shots)
Shot Distance (U/J) (How long the bullet stays alive for while on-screen, off-screen it goes away)
Shot Speed (I/K)

If you have a good set of numbers that you think works well, please let me know. I would like to get some feedback before progressing.