Machine Gun

The Machine Gun (マシンガン Mashingan) is one of the three possible replacements for the Polar Star, and is the earliest one available. 
The Machine Gun is a weapon used by Curly Brace, and she will use it when the player fights her in Sand Zone. Once she is defeated, and Quote says he is not a mimiga killer, she will offer to swap the player's Polar Star for the Machine Gun.
== Location ==
After Curly is defeated in the Sand Zone Residence, she will comment on the Polar Star being out of shape and offer to trade it for her Machine Gun. If the player declines this trade, Curly keeps the Machine Gun, but the player will be able to accept it later as long as Curly is still present in the Sand Zone Residence.
If the player never traded for the Machine Gun, Curly keeps it and uses it again in the Labyrinth. 
== Behavior ==
As an automatic weapon, the Machine Gun fires bullets as long as the Fire button is pressed down. When the Machine Gun is equipped, but it is not being fired, it automatically regenerates ammunition.
The Machine Gun is the only weapon which influences Quote's movement. More specifically, when aimed up or down, the recoil sends Quote in the opposite direction. In its level 3 form, Quote can hover by firing downwards as long as the Machine Gun holds ammunition. 
== Available trades and upgrades ==
At the Labyrinth Shop, the player can interact with Chaba while armed with the Machine Gun in order to obtain the Turbocharge. This upgrade is automatically equipped and decreases the delay in which the Machine Gun recharges its ammunition.
== Trivia ==
* A Machine Gun Challenge is present in Cave Story+ that can be completed before starting the actual game.
* The Machine Gun is one of two weapons that refills its ammunition automatically, the other being the Bubbline.
* This is one of the four weapons with limited ammunition, the other ones being the Bubbline, Missile Launcher, and the Super Missile Launcher.