Here is the full list of all 26 Half Past Disaster achievements.
Earn 10 stars
Complete the Jurassic Age
Complete the Ice Age
Complete the Ancient Egyptian Age
Complete the Medieval Age
Complete the Golden Pirate Age
Complete the Modern Age
Complete the Future Age
Finish the Game
Earn half the attainable amount of stars
Earn all attainable stars
Discover and complete the secret path within the Dinosaur's Domain
Discover and complete the secret path within the Mammoth's Tundra
Discover and complete the secret path within the Pharaoh's Tomb
Discover and complete the secret path within the Dragon's Castle
Discover and complete the secret path within the Kraken's Seas
Discover and complete the secret path within the Monster's Warehouse
Discover and complete the secret path within the Craig's Laboratory
Die 100 times
Go through 50 warp holes
Unlock 20 portals
Jump 500 times
Finish a level with less than 0.1 seconds remaining
Fall to your death with a shield equipped
Fall into the sky
Attain all secret collectibles from each boss's secret path