Unlike most video games on the market that encourages users to choose and upgrade any perks that appear fancy to them, Ixion demands its players to pick the upgrades to aid the questline. Due to this approach, the upgrade pattern of all players tends to be the same with little deviation. So, if you are a player trying too much and failing to progress due to poor upgrade selection, don't worry—we have curated the best chronological order of the Tech Tree Upgrade pattern that will help you reach the end screen without difficulty.
Ixion Tech Tree Upgrade Pattern Tier 0
All the Tech Tree upgrades in Tier 0 are fully unlocked by default in Ixion.
Ixion Tech Tree Upgrade Pattern Tier 1
Similar to Tier 0, most of the upgrades are unlocked by default except for the two buildings, Eva Airlock and Probe Launcher. For this, you can start with the Eva AirLock, followed by constructing a Probe Launcher.
Eva AirLock -> Probe Launcher
Ixion Tech Tree Upgrade Pattern Tier 2
Tier 2 is where the actual game starts. We recommend starting with Cryonics Center Upgrade, as you will need more people to expand into new sectors. After that, you can do the Battery upgrade followed by all three types of factories like Steel Mill, Polymer Refinery, and Electronic Factory. You can Swap for one of the factories with any Stability building upgrades like Memorials in case you lose Trust among your people.
Cryonics Center -> Battery Tier 1 -> Steel Mill -> Polymer Factory -> Electronics Factory -> Alternate Life Center -> Memorials -> Outer Hope Black Box(Mandotary)
Ixion Tech Tree Upgrade Pattern Tier 3
For Tier 3, you can start with something like a DLS center and go to Crop Farm or Cell Housing if you are having trouble with food or housing. But do anyone at a time. After that, you can start the Colonization Training Center as you might get the Test Colonization Protocols mission, followed by setting up a Fusion Station. Go for the Waste Treatment Center next and a Mushroom Wall. You can build a Legislative Strengthening Center before the previous two buildings if you are facing some Stability issues in one of your old sectors. Leave the Fire Station for the last as it is of little to no use.
Related: How to use Space Probes in Ixion
DLS Center -> Crop Farm/Cell Housing(situation-based) -> Colonization Training Center -> Crop Farm/Cell Housing -> Waste Treatment Center -> Mushroom Wall -> Legislative Strengthening Center ->Fire Station -> Protagoras Diagnostic Analysis(Mandotary)
Ixion Tech Tree Upgrade Pattern Tier 4
The last and final tier of upgrade is Tier 4. For this, you can start with the Train Station to help set up the remaining sector quickly. After that, you can construct a Health Center to help decrease the mortality rate, which should be rising by now. After that, you can make the Nuclear Power Plant and Water Treatment Center. Before these buildings, you can also build Algae Farms if you suffer from food shortages. The next in line should be the Drone Bay to speed up resource-sharing. For the rest of the perk-based building, you can build it depending on your deficiency or crisis at that time.
The Piranesi(Mandatory) -> Train Station ->Health Center -> Nuclear Power Plant -> Water Power Plant -> Algae farms -> Drone Bay -> Hull Temple -> Exo Fighting Dome -> Observatory
Remember, these suggestions are based on the main questline. You can always change one or the other upgrade to suit your playstyle or shortcomings.
For more on Ixion, check out How to maintain hull integrity in Ixion or How to transfer resources in Ixion on Pro Game Guides.