Speed across land and water in your own personal hovercraft. 2 versions, plus 2 more with the mod 'Laser Tanks'.
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.
I'm running Space Exploration with all the recommended mods, including AAI vehicles. The hovercraft fails to navigate obstacles like the AAI vehicles does, and instead runs into all objects, including belts. The belts then take damage.