Here is the full list of all 26 Lightyear Frontier achievements.
Explore 7 ruins.
Explore the vault in Outset Grasslands.
Increase Homestead Coziness to 3.
Restore all regions in Outset Grasslands.
Remove 700 Noxious Weeds.
Remove 150 Noxious Slimes.
Build the radio tower.
Plant 1000 seeds.
Remove 50 Noxious Slimes.
Plant 500 seeds.
Get 10 upgrades at the Upgrade Depot.
Feed 50 animals.
Remove 300 Noxious Weeds.
Feed 20 animals.
Remove 100 Noxious Weeds.
Increase Homestead Coziness to 2.
Plant 100 seeds.
Explore a ruin.
Get an upgrade at the Upgrade Depot.
Restore a region.
Remove 10 Noxious Slimes.
Scare away 10 animals.
Feed an animal for the first time.
Spray water at another player.
Plant your first seed.
Increase Homestead Coziness to 1.