The Chaingunner vehicle is essentially a Gun Turret on tracks. Turret creep has never been easier. Can be automated with the Programmable Vehicles mod.
Mods introducing new content into the game.
Transportation of the player, be it vehicles or teleporters.
New ways to deal with enemies, be it attack or defense.
My game will not start with this mod installed
What error message are you getting? Are you running the latest version of Factorio? If not try updating.