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