If you're wondering how many playthroughs...
I recently got all achievements on this game, and for anyone wondering how many times you have to complete the game to get every achievement, the answer is 5. I'll say that number again, FIVE. Three of them must be done with the hillbilly (and 2 different characters with him each time) to get fortune readings for every character, and you must complete the game with all other characters twice. The first (or second, whichever order you prefer) time you beat it with a specific character, take the item he/she desires out of the cave with you to get the "bad" ending, and the next time press X three times in front of the gift shop clerk to give it back, thereby getting the "good" ending with the same character and unlocking all cave paintings (12 for each character--8 found in the game, 2 for good ending, 2 for bad ending). Another pro tip: Do your "no deaths" run through on characters with minimal hazards in their levels. I did mine with The Twins, The Monk, & The Hillbilly. Happy Hunting!