Gamemodes
Northstar comes included with some community made gamemodes.
If you are looking for every available gamemode and its corresponding string check hosting/gamemodes

Gun Game

Get a kill with each gun to win.

Titan Tag

Earn points while in your titan. Destroy a titan to get your own.

Infection

Survivors are infected when killed.

Amped Killrace

Get kills to increase the length of your killrace. Collect the flag to start it. Set the record to win.

Fastball

Hack control panels to win rounds and respawn your teammates.
Before v1.5.0, some maps did not have control panels yet. These maps include Homestead, Complex, Glitch, Relic, Rise, and Crash Site. Make sure to update to v1.5.0 or later to have Fastball control panels on all maps.

Competitive CTF

CTF with custom settings for Comp games.