Here is the full list of all 27 Riftbound achievements.
Begin your journey
Start a battle with at least one upgrade
Complete all levels on Casual or higher difficulty
Complete all levels on Normal or higher difficulty
Complete all levels on Hard difficulty
Complete all optional challenge battles
Win 20 battles after the first boss fight without evolving any elementals
Win 20 battles after the first boss fight without using any primary spells or combo spells
Kill 20 Skeletal Enders
Win any standard battle after the first boss fight without using any AETHER type elementals
Have at least 9001 energy during a battle
Collect 500,000 energy
Win any standard battle with at least one elemental from all five elements on the battlefield
Win any standard battle after the first boss fight using only AETHER type elementals and spells
Use tactical spells to push, move or block 1000 enemies
Use interrupt spells on 500 enemies
Complete a darkness level without using any primary spells or combo spells
Defeat 2500 enemies of any type
Defeat 15,000 enemies of any type
Have 10 Tier 3 elementals on the battlefield at the same time
Win a battle with only 1 lane seal remaining
Have elementals on all 45 tiles at once during a battle
Win any boss battle without using any primary spells or combo spells
Defeat the final boss without using any upgrades
Cast 1500 primary spells
Cast 500 combo spells
Unlock all elementals