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