This game has a LOT of potential. Adding a few things such as a health bar (or Coolness Bar!), projectiles (both for the player and the enemy), Invincibility after dashing, Double jump and different types of enemies could make the game more complicated. Also getting power-ups after killing a certain number of enemies would be nice too, like getting a shuriken with every five kills.
The only annoying thing for me was the times I could dash at several enemies but the game chose the enemy near the edge of the screen leading to my fall. Anyway, great job!