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