Alright...

So you know how to make a sniper game, now you need to put a story, different maps, and mostly just a little more time into it.

Mouse training

Aside from what everyone else has stated, you know what this game really needs? A story. Some character development. Something that lets me know why I'm a sniper and picking off potentially innocent people on the street.

nice

First the good i liked the simplicity of it because it made a nice change to other sniper games to which i too enjoy
the bad was sometimes it was hard to find the people due to the limited viewing of the sniper scope. also you didnt get a notification saying if you were finished or anything so you didn't know if you were finished or not
i still liked it though and hope to see more flashes from you in the future :)

Great

Try harder. I killed everyone, but i got no gratification for my hard work.

mechanics are fine...

...but it needs a counter and/or a "congratulations" and reset when you shoot everyone.