Gun Girl 2

""It seems the Zombies have taken over the entire world!""

A girl with a gun wakes up after a night dreaming about puppies to find the world has been taken over by zombies!

Gun Girl 2 is a Freeware indie PC game made by Paul Schneider best described as Cave Story meets George Romero meets a gore-filled zombie apocalypse. Navigate a large interconnected world, shoot zombies, find upgrades to fight more zombies, shoot zombies, appreciate numerous horror movie references and shoot zombies!

Gameplay is Metroidvania-style and includes a weapon upgrade system akin to that in Cave Story. The game is available for free download here.

Particularly notable about the game is it's impressive soundtrack, composed by Josh Whelchel and available for free download at http://www.jwmusic.org.

This game contains examples of:

 * Action Girl: You did read the title didn't you?
 * Bonus Boss: The cultist twins.
 * Dark World: The "hell" areas that mirror the normal areas and sport rearrangements of their music.
 * Dead Weight: The chainsaw zombies and green slime zombies.
 * DVD Commentary: The creator has posted a playthrough on Youtube.
 * Flunky Boss: All but one will summon normal zombies to distract you while attacking, in fact this is the main source of difficulty with them.
 * But this is also a means for the player to potentially gain more ammo and health kits during the battle, so it tends to be a necessity.
 * Guns Akimbo: Max level pistols.
 * Harder Than Hard: Iron Maiden Difficulty.
 * Impossibly Cool Weapon: The sawblade cannon and self-proclaimed "ultimate gun", which include a railgun. The creator basically threw in whatever it would be cool to kill zombies with.
 * Luckily, My Shield Will Protect Me: One of the earliest upgrades you get in the game is a full-body ballistic shield that is surprisingly useful against zombie attacks. It has its own durability gauge, but with an additional upgrade, it becomes one of your trustiest gadgets.
 * Metroidvania: While certain areas can't be accessed until you proceed with the main plot, all areas are connected and there are plenty of hidden upgrades to find.
 * New Game+
 * One-Hit Polykill: With the Sawblade Cannon.
 * One-Winged Angel: The third form of the final boss.
 * Shotguns Are Just Better: Played straight; ammo is abundant, damage and rate of fire (see Good Bad Bugs) is high - there's little reason to use anything else.
 * Shout-Out: Numerous, including Cave Story and the Jason films.
 * Some are quite appropriate in the context, like having Ash, others make less sense. Mario? Link?
 * Shut UP, Hannibal: Your character will deliver one after hearing the villain's sob story.
 * Suspicious Videogame Generosity: When you see two special medkits in quick succession prior to the final boss you know you are in trouble.
 * Wrap Around: in one section of the Hell Marshes, you can fall down and reappear at the top of the screen. You are even advised upon entering that the laws of physics work differently there.
 * Zombie Apocalypse