Drone Wars 2.0 was made entirely from scratch and is technically a whole new game.
So what's new? Well literally everything, but here are some of the most important improvements 2.0 comes with:
New custom networking.
New and better movement which is now server authoritative, with client side prediction, server side reconciliation and server rewinding(lag compensation) and is thereby way more secure.
Humans are now a playable class.
The drone model has also been recreated from scratch and the overall look of the game has improved by a lot.
Way better looking UI (especially the main menu).
A voting system, so each player can vote for the next game mode at the end of each round.