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