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.
Opened The Hex.
Crashed Walk
Receive 4 card readings from Catarina in Walk.
Free Vallamir.
Crack all the vending machines at The Six Pint.
Wooed a Great Kraken.
Perform a 360 No Scope with the sniper rifle.
Discovered the truth about Mr. Shrewd.
Crashed Waste World.
Buy 10 upgrades from the Scrap Shop in Waste World.
Crashed Secrets of Legendaria.
Deal at least 500 damage in a single strike in Secrets of Legendaria.
Find Missing No. in Secrets of Legendaria.
Score a true KO on Alley Gator in Combat Arena X.
Score a 1000 hit combo in Combat Arena X.
Crashed Combat Arena X.
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.
Completed ???'s memory.
Help Rebecha survive the first wave in Walk.
Completed Lazarus' memory.
Completed Rust's memory.
Activate a gated mod in Waste World.
Completed Chandrelle's memory.
Crack a soda vending machine at The Six Pint.
Completed Bryce's memory.
Completed Super Weasel Kid's memory.