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