Here is the full list of all 24 Omega Strike achievements.
Defeat Doctor Omega
Defeat OmegaBot-2000
Open all chests in one game
Defeat the Garbage King
Collect all Life Cubes in one game
Defeat the Sky Commander
Defeat Garbage Disposal Unit X13
Defeat Colonel Gurtz
Defeat Overseer Brodus
Defeat the forest guardian
Find 10 Life Cubes
Open 10 chests
Defeat Drillmaster 5000
Buy a Grand Feast
Buy a Chicken Treat
Defeat Commander Armstrong
Buy a weapon upgrade
Defeat Wrassler
Collect 100 coins
Defeat Dozer
Collect 50 coins
Open a chest
Find a Life Cube
Collect 10 coins