Here is the full list of all 22 UltraGoodness achievements.
Unlock all companions
Defeat the Tree of Evil
Defeat the Machines of Terror
Defeat the Office Guy
Kill 100 enemies
Kill 500 enemies
Kill 1 000 enemies
Kill 2 500 enemies
Kill 5 000 enemies
50 enemies killed by flames
100 enemies killed by flames
250 enemies killed by flames
500 enemies killed by flames
1 000 bullets fired by the player
2 500 bullets fired by the player
5 000 bullets fired by the player
10 000 bullets fired by the player
50 bombs thrown by the player
100 bombs thrown by the player
250 bombs thrown by the player
Catch bunnies having fun
Be friends with Satan