The Into The Dark Add-on for The Riftbreaker has 6 achievements.
Dig through or destroy 1000 cavern walls.
Kill 30 Drillgors.
Kill 100 enemies with the crystal walls' explosion.
Set up 250 traps.
Open 10 bioanomalies in the Crystal Caverns biome.
Finish survival mode in the Crystal Caverns biome or the Into The Dark story campaign.