Steam says I have to wait until the game is released in order to do a review.
So, I created this thread to keep at least my review, so that I can post it on Steam later. Feel free to post your own reviews here for safe keeping.
I have been playing Zero-K on and off for a couple of years now (before it hit Steam). The game focuses on territorial control to gain the main resource ( Metal ). You use metal in factories, assist by using builder units to build faster, and build units and engage other players. All units play differently and have their natural strengths and weaknesses. There can be hundreds of units on the battlefield at a time, and you can zoom in and out as you wish.
You may thing it's like supreme commander, or planetary annihilation, or some other game inspired by Total Annihilation, there are many. However, unlike others, Zero-K has a flat technology tree, so you can, in theory, build any unit at the very start of the game. You are also not limited to your starting factory; there are no factions, but everyone has access to all factories.
Zero-K units also use real physics for movement and projectiles, so you can dodge rockets and artillery shells with fast-moving units, and jump away to avoid a bomber about to hit you. You can move units to a formation by simply dragging the formation with the mouse. You can make units join a group when they are created, so that you can easily add reinforcements to your main force as they are produced without having to go and manually select them. These features set a high bar for other RTS games, and I have not gone back to those since discovering Zero-K.
In addition, the Zero-K AI does not cheat. All of the above features make Zero-K a fun and diverse game to play. Oh, and it's free and open-source.