Since most of the feedback above is not useful, i'll dispense with my expert opinion instead.
Rather than make a long list of short bullet points, i'll make up three categories with long texts.
These will be game design, social engineering, and technical implementation.
Game DesignLast two Planetwars (counting the Galaxy Compressor Incident as separate from Synpact vs Dynasty round) before this one were warp rushes. This one attempted to remedy the ease of warp rush by limiting required dropship count for initiating a remote attack to at least 10 ships.
However, in practice this meant that instead of rushing a warp core fabricator and attacking with the first dropship, all i had to do was wait until i had 17 cores.
[Spoiler]Why 17? Each dropship gives 1 influence bonus, base influence is 35, influence needed to capture a planet is 50.1, fair battle win chance is say 50%, influence decay is 1 per turn if conflicting influence exists. 17 dropship gives 52 influence, decays to 51, and is just enough over 50. This gives you 50% "fair" chance of capturing the planet instantly. Contrast this with sending 20 ships in two fleets of 10 - this costs 3 ships more and give you only 0.25 chance to capture.
The case for warp rush is fairly obvious: warp can strike anywhere, including at built-up eco planets; if successful, it also prevents enemy from obtaining their own warp, bomber, and dropship capability forever, while also paying you hefty amounts in loot from selling their captured buildings.
All the slippery slope mechanics that contributed to making all previous two-faction rounds (including synpact vs dynasty) were still present.
Consider: a faction can expect to gain 35 influence from a successful attack; to perform 1 attack every two economy turns (every other is defense), and to win 50% of games assuming fairness. This means 35 influence per 4 economy turns. Now, each bomber kills 1.2 influence (expected value), so to kill 35 influence, you are going to need 29-30 bombers. To completely negate enemy's expected influence gain through bombers alone, you need to produce 7.5 bombers per turn. 15 bomber factories effectively negate enemy influence gain. This is all disregarding bomber capacity to make things easier for you by destroying enemy infrastructure.
Dropships are fairly similar. Each dropship gives you 1 influence, but you need only 17 dropships to turn an attack into one that captures the planet with one battle instead of two battles. If you output this much dropships every 4 economy turns, you can expect to score two victories when your enemy will score just one.
Warp merely amplifies all this by making it possible to apply these slopes to where it matters most: enemy eco worlds. Defenses being useless amplifies it further.
Consider the following defenses: Warp Jammer - takes 8 turns to power up, which is enough for the attacker to leisurely assemble a new warp invasion fleet and place it in orbit just as the jammer powers up. Field Garrison - takes 10 influence from attacker's victory, then becomes disabled by victorious invasion; against unassisted invasion this means that it turns 35+35 into 25+35 - that is, instead of spending two victories to gain the planet, the attacker has to spend two turns: the structure is useless in terms of actually preventing planet capture.
Offense is the only game, the first guy to shoot wins.
Social EngineeringMost of the players who were not veterans of previous PW seasons had no idea what was happening because of lacking documentation. Both factions lacked a government because noone was told to run for office before the season was launched. Both factions were imposed with their lore on the player base without much explanation, so noone was invested enough to recruit - so the faction which ended up with a hardcore clan won the recruit game by default. Unlike the Hegemony vs Rising season, noone even tried to make recruitment posters.
Consider: generation of metal in PW is mostly driven by player activity. Metal directly feeds into the slippery slope mechanisms above. Active players are everything the faction has: its economy, its soldiers, and its strategists. Losing the recruitment war is losing the war.
The lesson here is that factions (including their lore) should be engineered to have people capable of leading them and of attracting players. A way to achieve that is to ask players who they want to play with, and who they want to roleplay as.
Factions should have established and legitimate governments before starting the season. This can be achieved by whatever means, but i especially like the "struggle for power" pre-season tests. May the best emperor win in a mini-PW, or run a tournament, or whatever. This could be different for each factions for flavor. The current vote system is the worst possible method. It can be argued that elections allow the faction leader to be changed mid-season; however i would argue that seasons are now short enough for this to not matter.
Technical ImplementationThis was largely successful! Sure, there were bitrotten bugs all around (structures not being sellable, battles being counted five times, all kinds of names missing from logs, etc). Also a lot of stuff just went untested again (planet buster, galaxy compressor, guerilla jumpgate etc) - some are too expensive, some are suspected to be broken while also less useful than core fabs - for example, the guerilla jumpgate was never seen working to my knowledge at all.
Some "not serious" testing could be done before running proper rounds. The imperial civil war deciding who gets to be the new emperor sounds like a good approach both to create competent leadership and to test infra support.
Ideally, the galaxy map itself could reside in Chobby, and attackable planets highlighted. Barely anyone knew that you could attack planets by going to website and clicking anything within reach. This also allows all kinds of cool animations.