Complex is a free advanced game modification based on Relic Entertainment's Homeworld 2 game engine, free of any business directive, developed with passion and hard work, for experienced RTS players only. In a world of simplified games often under pressure to do well commercially, our challenge has been to create this ambitious project, for those who want more from a modern videogame.

RisingDivinity says

9/10 - Agree Disagree

For any commander looking for a challenge and depth in a strategy game, the complex experience should itch the scratch for those looking to lead their space fleet to victory.
Many extra elements of gameplay are added that ultimately balance out the core game. You can't rush destroyers if you don't have enough captains to, well, captain them. You also have to consider power for your capital ships, pilots for your new ships and manage your resources so nothing goes to waste!
Don't be put off by this, these things are easily handled by a single choice purchase of a ship or research and a little consideration.
So why play the Complex mod if it adds so much... complexity? Well there's the challenge of that complexity but there's also the increased scale and vast variety of ships that come along with it. You can capture planets to gain extra resources, build habitable super structures to house tax paying colonists and even build megaliths that spit out nukes and ultra long range ballistics that'll make you think twice before engaging your Mothership.
That is unless you've upgraded your flagship to be able to go toe to toe with even the scariest looking capital ships with increased armour and extra weapons. Indeed, even your immediate options are more varied than the base game in some senses.
My only critique with this is one I've had from the beginning: A bias towards the Hiigaran race has granted them with a great many more ships and options to build but the other side to this is that playing as the Vagyr is much more simplified and doesn't force you to build half a fleet in order to simply maintain production of new ships. This has been done intentionally to allow different playstyles but once you begin getting deeper into the mod, you'll notice the difference.
That's pretty much it though as the quality of work is astounding and the fun to be had is unforgettable. Remind yourself of what it was like blasting the enemy mothership for the first time with nothing but plasma and lance beams or when you flip the game on the head and pour resources into making the mothership itself the weapon you use to end the game. The choices are yours to make.