It has nice ideas. Every faction has different base building mechanics, tech trees (except aliens) and you can customize your units (well, most of them).

They did try to make each faction play differently. For example. the Eurasian Dynasty has a central industrial hub that expands using a series of pipes and tend to have an industrial, rugged look, the Lunar Corporation uses modular towers and have a more sleek sci-fi look with an emphasis on energy weapons, the UCS are all robots and also have modular buildings except they are built similar to how the Protoss build their buildings and they can teleport entire armies across huge distances, and the Aliens don't even build proper bases, instead several of their units can clone themselves and mutate into more specialized combat units, requiring only time and one of three resources. The only buildings they can make are defensive towers, which you use to defend your resource patches while you mutate.

They even differentiated how each faction collects resources; ED has flying drones that can just sit on a resource patch and provide a constant stream of income, LC uses mining facilities that can fly to a new resource patch and the UCS are more like your traditional RTS faction, with a refinery building that your worker robots go to after collecting resources.

However, for every brilliant idea they had they made several incredibly inept gameplay decisions.
One of the most infuriating is when the game takes away your ability to control it during dialogue but not pause it, so you get slaughtered. But at the same time there are dialogue sequences where you can control your units, so the devs clearly thought that stopping you from playing the game is a good thing.

There's also a lot of questionable balance choices, such as the Anti-Missile module not working against what are clearly missiles, shields only blocking energy weapons (thus leaving reflective armour useless) but making chem weapons incredibly lethal (except against aliens who deal mostly chem damage and tend to have high chem resist) and infantry being absolutely useless.

Faction wise the LC feels very weak, with slow resource gathering speed but fragile and expensive units. The Aliens on the other hand feel way too strong; despite requiring less resources their units are much stronger than most other factions. They aren't even fun to play, as most of their gameplay involves waiting. Since they don't have infrastructure or research, a lot of their gameplay involves waiting for bars to fill, clicking on individual units to clone and mutate and hiding behind long ranged OP defensive structures until you're ready to steam roll every other player with damage sponges that hit like trucks. So not only are they incredibly OP but they are also boring, and that's just sad.

The control and UI isn't great either; double click is an attack move, but at the same time you can just A move. Why both of those? Why not just the A move like a normal game? Double click for attack move just makes the game clunky, especially when its also how you command units to run. Its a game where you can design your own units, but there seems to be a cap to the number of designs, they aren't organized in the build menu and the icons all look the same. You can't see enemy stats so you don't know what armour and weapons they're using, so you have to just guess. That just outright kills the whole idea about tailoring your army to counter your enemy from get go.

The campaign can be pretty exhausting to play through; the missions are very long and there are many missions where the AI just spams armies so you have to constantly grind through them. And when it isn't a constant deluge of enemies they're incredibly easy; sometimes the AI barely attacks you.

The voice acting and music mixing isn't good. The music isn't as bad as Earth 2140 where it just starts suddenly playing smooth jazz over a massive battle, but it is pretty generic, a bit too loud and has a habit of drowning out the dialogue the devs want to force you to listen too by taking away your control.

Just stick to Command and Conquer or Starcraft. They are much more competently designed games.
Which is a pity, because this game did have a lot of potential and there are some fun moments. I really enjoyed the UCS campaign because they are really fun to play. Unfortunately, the Alien campaign (which is also the last one that concludes the story) wasn't as fun for the aforementioned reasons.

I should probably mention that despite what you may read you do NOT need to register to play the game and provide your personal info. Registration is completely optional and was a hold-over from a time when that was an option.
Starcraft, if I recalled correcty, did ask for registration, but much like Earth 2160 you didn't have to do it.
You do need to input a serial code (given to you by Steam, check your library) and it does give an activation code (which does nothing)? But no, you don't need to register.

It has nice ideas. Every faction has different base building mechanics, tech trees (except aliens) and you can customize your units (well, most of them). They did try to make each faction play differently. For example. the Eurasian Dynasty has a central industrial hub that expands using a series of pipes and tend to have an industrial, rugged look, the Lunar Corporation uses modular towers and have a more sleek sci-fi look with an emphasis on energy weapons, the UCS are all robots and also have modular buildings except they are built similar to how the Protoss build their buildings and they can teleport entire armies across huge distances, and the Aliens don't even build proper bases, instead several of their units can clone themselves and mutate into more specialized combat units, requiring only time and one of three resources. The only buildings they can make are defensive towers, which you use to defend your resource patches while you mutate. They even differentiated how each faction collects resources; ED has flying drones that can just sit on a resource patch and provide a constant stream of income, LC uses mining facilities that can fly to a new resource patch and the UCS are more like your traditional RTS faction, with a refinery building that your worker robots go to after collecting resources. However, for every brilliant idea they had they made several incredibly inept gameplay decisions. One of the most infuriating is when the game takes away your ability to control it during dialogue but not pause it, so you get slaughtered. But at the same time there are dialogue sequences where you can control your units, so the devs clearly thought that stopping you from playing the game is a good thing. There's also a lot of questionable balance choices, such as the Anti-Missile module not working against what are clearly missiles, shields only blocking energy weapons (thus leaving reflective armour useless) but making chem weapons incredibly lethal (except against aliens who deal mostly chem damage and tend to have high chem resist) and infantry being absolutely useless. Faction wise the LC feels very weak, with slow resource gathering speed but fragile and expensive units. The Aliens on the other hand feel way too strong; despite requiring less resources their units are much stronger than most other factions. They aren't even fun to play, as most of their gameplay involves waiting. Since they don't have infrastructure or research, a lot of their gameplay involves waiting for bars to fill, clicking on individual units to clone and mutate and hiding behind long ranged OP defensive structures until you're ready to steam roll every other player with damage sponges that hit like trucks. So not only are they incredibly OP but they are also boring, and that's just sad. The control and UI isn't great either; double click is an attack move, but at the same time you can just A move. Why both of those? Why not just the A move like a normal game? Double click for attack move just makes the game clunky, especially when its also how you command units to run. Its a game where you can design your own units, but there seems to be a cap to the number of designs, they aren't organized in the build menu and the icons all look the same. You can't see enemy stats so you don't know what armour and weapons they're using, so you have to just guess. That just outright kills the whole idea about tailoring your army to counter your enemy from get go. The campaign can be pretty exhausting to play through; the missions are very long and there are many missions where the AI just spams armies so you have to constantly grind through them. And when it isn't a constant deluge of enemies they're incredibly easy; sometimes the AI barely attacks you. The voice acting and music mixing isn't good. The music isn't as bad as Earth 2140 where it just starts suddenly playing smooth jazz over a massive battle, but it is pretty generic, a bit too loud and has a habit of drowning out the dialogue the devs want to force you to listen too by taking away your control. Just stick to Command and Conquer or Starcraft. They are much more competently designed games. Which is a pity, because this game did have a lot of potential and there are some fun moments. I really enjoyed the UCS campaign because they are really fun to play. Unfortunately, the Alien campaign (which is also the last one that concludes the story) wasn't as fun for the aforementioned reasons. I should probably mention that despite what you may read you do NOT need to register to play the game and provide your personal info. Registration is completely optional and was a hold-over from a time when that was an option. Starcraft, if I recalled correcty, did ask for registration, but much like Earth 2160 you didn't have to do it. You do need to input a serial code (given to you by Steam, check your library) and it does give an activation code (which does nothing)? But no, you don't need to register.