The new ships, naturally, are the most important to the players. While the game nominally adds 140 ships or so, the actual count is much lower, as each ship has around five tech levels. The majority of the new ships fall under the Zenith category. These ships have a longer range, hit harder, and have average armor, making them the powerhouses of whatever fleet you decide to bring them along with. It's very satisfying to roll in with a fleet of normal ships, clear a beachhead, then bring in a Zenith fleet and watch as it wipes out all enemies in the system from a ridiculous distance. Our personal favorites are the AutoBombs and Grenarde Launchers, simply because it's ard not to love ships which cause splash damage. However, the AI gets them as well, and will most likely put them to better use initially, so be prepared to die a lot.
The other kind of ship that makes its first appearance in Zenith Remnant are the game-changing golems. These ships are ridiculously powerful to the point of breaking the game. They can only be acquired by turning on the Broken Golems minor faction, and doing so includes a seed of a few decrepit golems scattered around the galaxy map. Only the player can activate them, which is nice, but the AI player can send golems against you if you use the proper faction or AI type. They are essentially superweapons that can be used to turn the tide, and on the easiest setting make a game much more entertaining for a casual player.
Speaking of minor factions, there's a few others besides the golems. The most important to a player's strength, however, are the Zenith Trader and Zenith Dyson Sphere factions. The trader functions much like a trader would in any other game: you buy from him when he's on your planet, and his stock changes as he travels. The ships you can get from the trader are always ones that you can normally only get via capturing a planet, which makes him quite the asset. Unfortunately, he also has no qualms about selling to the AI as well, which makes taking enemy planets that much more difficult. The Dyson Sphere acts like a stationary indestructible hive of angry Zenith ships, and it perpetually attacks both the AI and players until the player takes out the command station on the Dyson Sphere's world. As long as the player does not try to colonize said planet, the Dyson Sphere then turns around and starts attacking on the AI, providing a significant defensive and minor offensive boost for players. Besides these two, there's also the Devourers and Miners, which are both destructive and always harmful to the player. We'll let you figure them out.
Zenith Remnant provides a ton of new content for players to sink their teeth into, and it's an excellent addition to the AI War franchise. With an entire new faction to play with, essentially (the Zenith), tons of new ships, game-changing minor factions, and a slew of other minor additions in the realm of AI types, map styles, and AI units. If you have AI War, this expansion is a must purchase, and paves the way for the next two in terms of difficulty. We suggest you get this expansion first and play it before getting the rest, simply because it will give you a good idea of the difficulty spike you can expect.
As for the expansion itself, it is much like the rest of the expansions: new ships, minor factions, AI goodies, AI plots, and map styles. There's less of them, but there is at least one new element in each normal expansion area. The most important, however, are the new ships and minor factions. The ships are almost all Neinzul Younglings, which are swarmer-style ships with extremely short lifespans. Conversely, they are cheap and fast, making them good harrassment or shock troop ships. There's also a Neinzul transport, which keeps the Younglings alive until they are unloaded, making it one of the most essential ships for anyone aiming to utilize the new Neinzul ships. The minor factions also revolve around the Neinzul, and each minor faction is almost completely neutral. The Neinzul apparently don't care who they attack. They want the galaxy to themselves!
It's a good micro-expansion, but tricky. There's not a whole lot of content, and the content that is there relies on principles that most players will likely pick up from Zenith Remnant or Light of the Spire. It also significantly increases the difficulty of the game, as AI using Neinzul ships is far more dangerous than the vanilla AI. We recommend picking this expansion up, but doing so after you have bought and tried out the other two. It's better as an addition to the already existing expansions, which makes sense given its status as a micro-expansion.
The new player-usable ships for Spire fall under two categories: the normal bonus ships and Spirecraft. Much like the golems of Zenith, Spirecraft are a minor faction that can be added to the game. Enabling it seeds a number of asteroids around the galaxy that, when a factory is built on them, allows the player controlling it to produce the powerful Spirecraft. Spirecraft are generally much stronger than normal ships, and most are stronger than starships, which makes them an essential strategic resource. However, both the Spirecraft and the normal Spire ships focus on alternate ways to fight rather than simply attacking. For example, one Spirecraft (the Attritioner) has weak main guns, but causes significant attrition damage over time. Another good example is the Spire Armor Rotter, which weakens ships for other, more direct attackers to take advantage of. As such, the Spire ships (unlike Zenith ships) don't really replace existing craft so much as augment established strategies.
The two largest additions in Light of the Spire are the new campaign types. If the player owns and enabled the Spire expansion, he now has access to (essentially) three separate campaign types. The best part about these new campaigns is that they work with the existing procedural generation system. The two new campaigns are Defender, which is much like an AI War version of the classic Survival game type (survive against overwhelming odds for a certain period of time), and Fallen Spire. Fallen Spire is especially excellent, as it is a scripted (has a story) campaign that works beautifully with random maps. The gist of the campaign is that you work with the Spire to bring them back to their former glory to gain an ally in the fight against the AI. It's difficult, but quite rewarding, and you get access to some pretty significant new ships even if you don't complete the alternate victory conditions.
The last major addition is in the realm of the AI itself. Whereas the previous two expansions did not do as much for the AI as they did for the player, Spire focuses on giving the AI a plethora of new tools. Most of these are the new Guardians, mobile ships that wreck havoc on any players that enter their system, but it also includes new AI types. For example, the Carrier Guardian absorbs damaged enemy ships until it has a large number, then makes its way to the player's homeworlds packed to the brim with dangerous AI combatants. In general, Spire increases the difficulty of the AI far more than Neinzul or Zenith do, which makes it the most difficult and rewarding of the three existing expansions.
Spire is our personal favorite expansion, but due to its difficulty, we suggest getting it after spending some time with Zenith Remnant. The new campaign types are significantly harder than the core game, and the additions to the AI's arsenal take a heavy toll on inexperienced players. The sheer variety it adds, though, is extremely impressive. If you feel daring enough, this is the expansion that we recommend highest of all three. Just don't get frustrated if the AI stomps you into the dirt over and over.
Across all three expansions, Arcen Games has shown that they know what players want from AI War. Everything from new ships to new AI routines are added in each expansion, and any player that enjoys AI War would be remiss not to get any of these. They are all must purchases. As mentioned, our personal favorite is Light of the Spire, thanks to the new campaigns and AI improvements, but any (or all) of the three are worth owning. They are perfect examples of what an expansion should be.