I like this kind of game. I see two problems: (1) The aim for the gun is slightly off. If I put the cursor on the gold disk, the bullet goes a little under it.. There is a limited amount of ammo, which isn't a bad thing, but bullets are wasted trying to figure out the right aim angle. (2) The bombs are a bit sluggish. Those are the only reasons I rated a 4 instead of a 5. Like the music, like the graphics.
Suggestions: (1) fix the aim. (2) give the bombs just a bit more oomph. They look more like bombs than grenades. Grenades have a little bounce to the ounce. These are just ...dead...like mush.
Good game otherwise.