This game is very fun and I'd recommend it to anyone looking for a quick fun experience. I do however have a few things I'd like to maybe see in the game one day:
Menu system - Currently the only menu is the one before the gameplay actually starts, and I feel like a pause menu or a options menu would be beneficial to the gameplay experience.
High scores - While you can earn a total score for playing the game it doesn't actually mean anything at the moment because it resets after you die. I feel a high score next to your current score (Maybe have the background be gold instead of red so you can differentiate the score types easier) would add more of an incentive to build up your score.
Skins / Themes - It does sound a bit cliché, however I do feel that a skins or themes system tied to your high score would be beneficial to the gameplay experience, and add more of an incentive to get a higher score.
Now that I have said some of my ideas that could be added, I'd like to quickly go over a bug I noticed. I played the game for a bit and noticed that the black target (Shown in the tutorial or first level) never appeared again, I'm not sure if this is because my score wasn't ever high enough (I got a high score of 50) however I feel the addition of this target would improve the gameplay, or at least make it known that it unlocks after a certain score.