Here is the full list of all 15 Halftime Heroes achievements.
Reach 10 strength
Get a score of 18 or higher when throwing the dices
Reach 10 luck
Add four modes to a new game
Reach 10 agility
Add one mode to a new game
Reach 10 willpower
Reach 10 wisdom
Reach level 10 in any spell
Kill 5000 monsters in one playthrough
Get any stat to 10
Reach 10 intelligence
Kill 3000 monsters in one playthrough
Kill your first boss
Kill 1000 monsters in one playthrough