Meh... I'd keep trying way more if there were some kind of HP instead of only one hit to die... Interesting idea, though!

It could be interesting, but, sadly, there is no much content.

So I actually really liked this game.

The idea was very original (at least to me).
At first, I thought, "meh", but then I lost and thought, "let me try again" and soon I had tried many times. It's the type of game that you lose and get mad and want to do better so you keep playing. The game play is really nice too (for example, you can't deflect 4 bullets so you actually have to move around) and you have to make sure you deflect back directly at them; all of this makes it challenging (thus fun) yet not too difficult.

One suggestion I do have is to make some system of "levels".
I feel that if players are playing not only for a 'high score' or 'fun', but also to like advance levels, it gives a sort of completion [btw, I like RPG/adventure games most so this might be a bit biased]. But imagine like after 5000 points in the first round, you go to another round...and the next round has a different layout and could perhaps be even harder (more enemies / different types of enemies?). You can even consider that the enemies drop gold and you have a 'shop" type of system to buy upgrades; I feel that this could make the game go really far!

But even without these additions, it is a fun/addicting game!