Here is the full list of all 28 Scrap Bastion achievements.
Die once
Die 10 times
Die 100 times
Win 2 times
Win 10 times
Win 100 times
Get 100 Kills
Get 500 Kills
Get 1000 Kills
Win Once With Leg Movement
Win Once With Car Movement
Win Once With Tank Movement
Win Once With Hover Movement
Win Once With Airforce Core
Win Once With Army Core
Win Once With The Armored Core
Win Once With The Engineer Core
Have 12 tech type weapons. Unlocks Mad Scientist
Have 12 Conventional Type Weapons. Unlocks The Marshal
Have 12 Primitive Type Weapons. Unlocks The Predator
Have 5 turrets with 10 upgrades each. Unlocks the perfectionist
20 Or More Of A Weapon. Unlocks The Gun Smuggler
Die 30 Times. Unlocks The Fool
Have 3 Swarm Missiles With 5 Upgrades Each In Custom Mode
Have 5 Labs In Custom Mode
Have 5 Lookout Towers in Custom Mode
Have 5 Greenhouses In Custom Mode
Have 5 Engineers Guilds In Custom Mode