Here is the full list of all 15 Hunter's Legacy achievements.
Beat the game without a single upgrade
Talk to all inhabitants of Iripur
Finish the game
Achieve a 100% game completion
Find all hideouts of Rampelkimpers
Acquire all bow upgrades
Find all ores in the game
Acquire all sword upgrades
Activate all teleporters
Collect a total of 2500 currency
Upgrade your wallet to its fullest
Acquire all health upgrades
Shoot 300 arrows
Make a Kobold drop its shield
Kill 200 enemies