Here is the full list of all 18 Capsized achievements. It takes around 10-12 hours to unlock all of the achievements on Windows.
Win 5 deathmatches with Bots
Beat every level without dying
Complete all levels in COOP
Finish a duel match with a local player
Complete a level in COOP
Get at least 4000 points in Survival arcade mode
Complete a level in the Armless arcade mode
Get at least 100 stars in the campaign
Find all secrets in the campaign
Get 10 stars on one level
Get at least 60 stars in the campaign
Complete 5 levels without firing a shot
Get at least 40 stars in the campaign
Kill all enemies in 5 levels
Get at least 20 stars in the campaign
Beat a level without dying
Kill 50 enemies
Find a secret area