5 levels are not enough
The game also has a auto fire on/off option, so thats pretty nifty. You also have choice of two characters : Walter and Tyra.
The game has some nice Action movie like music.
Weapons in Metal Slug Advance include shotguns, Molotov cocktails, machine guns, rocket launchers and more.
If you don't mind its short lifespan then Metal Slug: Advance is a great addition to your GameBoy collection.