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