Instead of using Q & W for dash, you could implement ←← / →→ for dash ... it is more comfortable.
The animation of the dash gives very little time invincibility to the player, but the recovery animation leaves him too vulnerable, not forgetting that the distance is somewhat short ... if it is part of the gameplay it leaves a little useless the dash to dodge to the enemies.
The enemies have an animation and art style that does not fit with the player character and environment, the only one that is exempt is the boss.