Here is the full list of all 20 Rainbows, toilets & unicorns! achievements.
Vegan Defeated!
Nikky Mouse Defeated!
Donut Man Defeated!
Long Ears Defeated!
Flat Earth Defeated!
No Vax Defeated!
Tanned Toupee Defeated!
Kill 450 Enemies in a Run
Use Magnet 10 Times
Nuclear Guy Defeated!
Macho Man Defeated!
Use Rainbow 10 Times
Salt Man Defeated!
Use Double Shot 10 Times
Influencer Defeated!
Use Shields 10 Times
Streamer Defeated!
Spoiled Child Defeated!
Gold Boss Defeated!
Flying Carpet Defeated!