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