Gunstar Heroes

Really easy, but if your having trouble play on easy with the "chaser" weapon that homes in on opponents (green weapon)

This achievement is easy enough, you'll unlock it by defeating the second boss of the first level, you'll come to find that in Gunstar Heroes you're able to almost mindlessly run through the levels holding down the fire button.

The only thing that really matters is which weapon you choose to use, I'd recommend either the homing bullets (the small green arrows) or the flamethrower weapons, the homing bullets will take out enemies without you having to aim in their direction constantly while the flamethrower inflicts the most damage, you also have the ability so save whenever you want, make good use of that!

* ^{Credit to SerenityWind the video}

Papaya Dance is the first boss you will encounter in the first level.

If you have the green chaser weapon then simply hold x up at the same time while dodging the balloons.

If you are without the green chaser weapon then stand directly underneath Papaya Dance and shoot up. If a balloon is about to hit you then dodge it.

Without too much effort this achievement can easily be yours.