Here is the full list of all 50 Kobold Castle achievements.
Finish Round 7 without letting any normal gnolls fully ascend a ladder
Have Plinko finish off the first 4 bosses in one run
Pet the Hyena
Die to a Chicken
Have a wizard kill 5 or more of it's fellow gnolls
Avoid taking damage for the first 10 rounds
Remain powered-up continuously for a full minute
Select all unique potion upgrades in a single run
Get 10 upgrades on the first round
As Stabby, finish off the first 4 bosses in a run with a powerup stab
As Stabby, beat the game without knocking down ladders until the Mopup Phase
Survive Round 5 as Stabby
Survive Round 10 as Stabby
Survive Round 15 as Stabby
Survive Round 20 as Stabby
Survive Round 25 as Stabby
Survive Round 30 as Stabby
Survive Round 35 as Stabby
Survive Round 40 as Stabby
As Punchy, kill a boss using only damage from punches
As Punchy, kill 30 enemies in a round without throwing a punch
Survive Round 5 as Punchy
Survive Round 10 as Punchy
Survive Round 15 as Punchy
Survive Round 20 as Punchy
Survive Round 25 as Punchy
Survive Round 30 as Punchy
Survive Round 35 as Punchy
Survive Round 40 as Punchy
As Shooty, kill 50 enemies in 3 seconds or less
As Shooty, kill 10 ranger gnolls in one round, without getting hit by any bolts
Survive Round 5 as Shooty
Survive Round 10 as Shooty
Survive Round 15 as Shooty
Survive Round 20 as Shooty
Survive Round 25 as Shooty
Survive Round 30 as Shooty
Survive Round 35 as Shooty
Survive Round 40 as Shooty
As Smashy, finish off the first 4 bosses in a run with your helmet
As Smashy, beat the game without touching the floor on any round after the first
Survive Round 5 as Smashy
Survive Round 10 as Smashy
Survive Round 15 as Smashy
Survive Round 20 as Smashy
Survive Round 25 as Smashy
Survive Round 30 as Smashy
Survive Round 35 as Smashy
Survive Round 40 as Smashy