I've got a soft spot for Tower Defence games, I remember spending a good about of Warcraft 3 playing Element TD and some version of Tower Wars. Despite the gameplay having waves and wave of enemies throw themselves into your carefully mazed defences being so fun, it was not as commercially appealing as DOTA. As such there is few games that ever match the enjoyment from the classic Tower Defence mods of Warcraft 3.
Mindustry is does just that though. Offers a solid Tower Defence with endless enemy waves and a sandbox resource management tech tree that allows for a lot of frantic moments and creativity. I've mostly played solo, but there is a live multiplayer scene accessible via their Discord. The fun comes from loading into a map, find the spawn point, setting up a frontline and snaking your mining, liquids and ammo to where it's needed so that you can take down each wave and get out with as many resources as possible to unlock more of that tech tree.
While the game is available for free via Github I wholeheartedly recommend purchasing it from Steam or Itch.io to support the developer.
