Here is the full list of all 35 Extremely Powerful Capybaras achievements.
Refund an Ability Upgrade for the first time.
Enter a run for the first time.
Evolve the Warrior to Barbarian.
Open a total of 5 Pots.
Die a total of 5 times.
Reach Level 30 in the Fishy Swamp.
Reach Level 30 in the River Rat's City.
Win a run for the first time.
Defeat a Boss a total of 5 times.
Evolve the Bard to Singer.
Win 2 runs in the Fishy Swamp.
Win 2 runs in the River Rat's City.
Evolve the Assassin to Rogue.
Equip 4 different Passives in a run.
Equip 4 different Weapons in a run.
Reach Level 40 in a run.
Evolve the Druid to Seer.
Purchase 5 Ability Upgrades.
Defeat a total of 50000 enemies.
Survive a total of 15 minutes with any class.
Survive a run in the Fishy Swamp.
Survive a run in the River Rat’s City.
Purchase all Rank upgrades for any Class.
Spend 2000 Capy-Coins in the Ability Shop.
Purchase a Class Upgrade for the Warrior.
Purchase a Class Upgrade for the Bard.
Purchase a Class Upgrade for the Assassin.
Purchase a Class Upgrade for the Druid.
Purchase a Class Upgrade for the Mage.
Purchase a Class Upgrade for the Gunslinger.
Clear a run in the Volcanic Springs for the first time.
Finish a run with Frenzy Level 1 or higher.
Finish a run in the Fishy Swamp with Frenzy Level 10 or higher.
Finish a run in the River Rat's City with Frenzy Level 10 or higher.