Here is the full list of all 20 Crunky's Fun Rager achievements.
Kill 100 Crunkos to earn their Michaelnomicon Entry
Kill 100 Crinklies to earn their Michaelnomicon Entry
Kill 100 Crangos to earn their Michaelnomicon Entry
Kill 100 Crongodongo to earn their Michaelnomicon Entry
Kill 100 Crungulian to earn their Michaelnomicon Entry
Kill 100 Cringe to earn their Michaelnomicon Entry
Kill 100 Crunkleon to earn their Michaelnomicon Entry
Kill 100 Critty Crat to earn their Michaelnomicon Entry
Kill 25 Turnip Boys to earn their Michaelnomicon Entry
Complete every entry in the Michaelnomicon
Conquer the Crunkopolis Plains
Conquer the Crumpy Desert
Conquer the Cropular Underground
Conquer the Frunky Fields
Kill 1000 Crunko Pops in Total
Die 100 Times in Total
Collect 1000 Coins in Total
Collect 50 Letters in Total
Collect 50 Powerups in Total
Complete a Run with a Total Score of 100,000 or more