Here is the full list of all 30 Tamageddon achievements.
Defeat the 10 minutes boss in Rolling Hills
Defeat the 10 minutes boss in Oddball Dunes
Reach level 5 with Spiky Ringson
Reach level 7 with Aimy Roundsman
Defeat the 10 minutes boss in Rocky Highlands
Defeat the 10 minutes boss in Roundabout Shores
Reach level 20 with Aimy Roundsman
Reach level 20 with Spiky Ringson
Reach level 20 with Scrapy Hoops
Kill 1 000 000 enemies
Reach level 10 with Orbus The Daring
Reach level 20 with Orbus The Daring
Find all map fragments
Defeat the 15 minutes boss in Rolling Hills
Defeat the 15 minutes boss in Oddball Dunes
Defeat the 15 minutes boss in Rocky Highlands
Defeat the 15 minutes boss in Roundabout Shores
Defeat the 15 minutes boss in Molten Disc
Defeat the 15 minutes boss in Marble Pathway
Reach rank 5 with Target Gun
Earn 30 experience coins in a single game
Earn 30 gold coins in a single game
Survive for 20 minutes
Survive for 25 minutes
Kill 50 000 enemies in a single game
Reach level 40 in a game
Reach level 50 in a game
Find all map fragments in Marble Pathway
Defeat the 10 minutes boss in Molten Disc
Defeat the 15 minutes boss in Frosty Hummocks