Nice little game. The visual effects and background music created a great atmosphere.
The gameplay felt a little to simple because there was nearly no challenge. The enemies are too predictable, don't try to attack or avoid damage. There is also no environmental hazard (spikes for example) that could have worked in combo with the fixed enemy movements. Paths could also be used as guides instead of constrains, that the enemies steer towards while moving freely.
Also the enemies defeat didn't feel rewarding because they disappear with no animation or particle effect. In contrast the player controls are nice and responsive and give good visual feedback through the trail effects.