While excellent in many respects, this game has a few hiccups that keep it from meeting its full potential.
Despite a nicely done graphical overhaul and finely tuned play mechanics for each side, the game, on the surface anyway, seems much simpler. Away with are the engineering options (tunneling, ditches, etc) and expansive research tree. The tunneling will not be missed, as it was clunky in 2150 and was not used much. The research tree, upon further inspection, is actually very well done. Much of the research in 2150 consisted of chassis and weapon upgrades, and the chassis upgrades have been done away with in this version, which is not bad, it equates to a slimmed down tree that can actually be well researched in multiplayer.
Much complexity and tactics have been added as well. Infantry are a huge addition, with the ability to capture buildings and enter vehicles. The tech trees, unit types, resource gathering, and even building style is well varied over the 4 sides. Heroes and virtual agents (mercenaries) are a great addition too, and can be customized with weapons, armor, and items.
I do have a few complaints, though. The difference between buildings and units are vast in terms of armor. While logical, it makes for awful gameplay when assaulting an enemy base. Your units designed to tackle enemy units wil automatically target buildings as well, firing away and doing little to no damage, all the while getting pummelled by the actual enemy units and base defenses. Units will also go out of their way (with 'auto engage enemy' on) to attack enemy units, even through an enemy defensive position. Keeping your friendlies out of range of enemy defenses while your artillery kills it is a full time job, and often futile.
Pathfinding is generally good, but like noted above, can be easily sidetracked. The soundtrack is decent, but the voice acting is horrible, as in 2150. Along with that, the single player campaign missions are varied, but not paced well, and the story could definitely use an actual professional writer. Also in the campaign, an annoying even is anytime story elements insert themselves into the middle of a mission. A window will pop up with various people talking and you lose control of all your units, though the battle is still raging. I have lost whole task forces (or heroes) through this mechanic due to the previously mentioned bad individual unit AI. The computer opponent AI isn't much better.
The multiplayer and skirmish is where it's at in this game, although even skirmish isn't up to par. Without mods to the game, you cannot ally with a computer, and when you start a match, all computers will be after you! This is a simple setup in the skirmish loading screen, and is pretty standard nowadays, and is a mystery why it wasn't included out of the box.
All in all, the sides are very well-balanced in terms of variety and playing styles, the research and unit customization are well done, but technical problems prevent the play to be very smooth. Nothing a few patches couldn't fix, however.