The controls would have been better if the dashing was combined with the movement keys. It felt very difficult to move was WASD as well as prepare dashes with arrow keys (largely because you had to be in the air to execute them with enough health). Probably just a double tap would accomplish this (so in update loop you always move left/right depending on A and D but if A is down twice within X time, and you have enough HP, you dash).
The game is also very difficult and could use a difficulty ramp with levels to introduce how the enemies are dealt with, and tips on inverting the map and dashing.
In general though great job. It looks really cool, and the dash sound effects feel very good.