Here is the full list of all 12 Amogus TD 2 - there are Defense of the Sus achievements.
Beat your first map
Beat every map on easy difficulty
Beat every map on normal difficulty
Beat every map on hard difficulty
Beat Road map only with Amoguses without upgrades
Kill 100 enemies
Kill 1000 enemies
Kill 10000 enemies
Beat the game with only one tower at the time
Buy second upgrade to Colossus
Beat desert map on hard difficulty
Kill 25 enemies within 5 seconds