Here is the full list of all 28 The Hex achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
Buy 10 upgrades from the Scrap Shop in Waste World.
Crashed Combat Arena X.
Opened The Hex.
Completed ???'s memory.
Crashed Walk
Help Rebecha survive the first wave in Walk.
Receive 4 card readings from Catarina in Walk.
Crack all the vending machines at The Six Pint.
Free Vallamir.
Completed Lazarus' memory.
Wooed a Great Kraken.
Perform a 360 No Scope with the sniper rifle.
Completed Rust's memory.
Crashed Waste World.
Discovered the truth about Mr. Shrewd.
Activate a gated mod in Waste World.
Completed Chandrelle's memory.
Deal at least 500 damage in a single strike in Secrets of Legendaria.
Crashed Secrets of Legendaria.
Find Missing No. in Secrets of Legendaria.
Crack a soda vending machine at The Six Pint.
Completed Bryce's memory.
Score a 1000 hit combo in Combat Arena X.
Score a true KO on Alley Gator in Combat Arena X.
Completed Super Weasel Kid's memory.
Crashed Super Weasel Kid '09.
Learn all of Catarina's secrets in Super Weasel Kid.
Complete the original Super Weasel Kid without any help from Mr. Shrewd.