Mediocre at best because of how imbalanced the classes are. The marshmellow starts with 1 in wisdom and health (health is alright) and ZERO potions. The elf starts with looting and skill and 1 potion.
The HUMAN STARTS WITH THREE POTIONS! The first level of skills costs next to nothing but potions always cost a flat 500 so the human starts with 1500 gold invested in him. Thus ALWAYS BUY HUMANS.
Second, don't upgrade skill or wisdom until last. They only speed up the heroes path to death and drain your gold. First max looting, then health. Looting = more gold, health = more adventures completed before needing to buy a potion. This game is basically potion management.
Once your first hero's looting is at 3 or higher and their life is 2 or higher you can safely get another human and do the same. Rinse repeat win. Try to get all the slots filled before turning in town quests so you can lvl your heroes to max for free.