This game has quite the story behind it. When Supreme Commander 2 turned out as a dud, some of the people behind it left to form another company, and put together some ideas for a spiritual successor. Since the 2012 crowdfunding rush was in full swing, they launched Planetary Annhilation. After being quite expensive in early access, it came out to mild praise some time later. In 2015, they launched an expand-alone, Titans. This was a substantially discounted paid upgrade to existing players (original backers got it for free), and they discontinued sales of the original.
I got the original in a Humble Bundle many years ago, then the expand-alone in a later one. Years ago (before Titans maybe), I tried this out. I started a campaign, and played about 5 missions. I felt that I was playing with Legos on a golf ball sized planet (if I was lucky, a basketball sized one). I was disappointed that even the minuscule maps on Supreme Commander 2 maps sometimes felt bigger. The tech tree consists of "data caches" found in each system. The problem is that you only have a fixed number of slots to fit them in. Granted, some upgrades are themselves more slots, but it's too easy to not have enough. I put it down until now.
After selecting your landing zone, your commander unit blasts in like Supreme Commander. From there, you base buildy and army fighty until your opponent commander units explode. Every map is a planetary system with one (if small) planet, and maybe more. Everything is fully rendered, so sometimes if you're zoomed out, a planet will float by in the background.
When you start a campaign, you can choose between one of about six identical factions. There doesn't seem to be any advantage or unit type differences between them. In this future, there are only robots. Humans are nowhere to be found, with no explanation given on what happened to them. Along with adding some smaller units to fill out useful roles, the Titans expansion adds much larger sized units (as the name implies). These are reminiscent of the experimental units from Supreme Commander (and much bigger than in 2). It turns out that these robots don't have much compunction against destroying planets. This can be done in few ways: nuking the planet's core, smashing planets into each other, or by building a death star.
The campaign starts you off at the corner of a galaxy, with the goal of fighting through it all (or at least, annihilate opposing faction leaders). It gets boring sometimes when several missions in a row will happen on an identically laid out planet. Since I have the base game and Titans, I played campaigns in both. When I started Titans, the maps were artificial and rigidly designed, and the original had more organic layouts. But that was short-lived: a few missions into Titans, some organic maps started appearing. Later on in the campaign, your opponents bring in friends to help cover larger planetary systems. If you let games go on for too long, some will escape to other planets, so you will have to adjust your strategy. Some upgrades that I had foregone earlier re-appeared from time to time, so don't worry if you have to forego one desirable upgrade in favor of another. If anything else, it's safe to aim for two empty tech slots, so you don't have to delete tech for something else.
When choosing your next fight, a description of your opponent appears. Almost every one would ascribe an advantage, flaw, or strategy to that commander, but I never noticed any differences between them. I noticed some unique commander and planet names that had a certain randomness. I'm guessing those were part of a Kickstarter backer reward tier. (Examining the reward tiers, I was right!)
I can see some potential for this. It evolves some ideas set forward in Supreme Commander, but it doesn't feel big enough. Sure, planets sound huge, but all of them together feel smaller than Debris.