Am I not supposed to be able to adjust the difficulty settings in this game? I went to the ini file and found there's a line for "difficulty" set to 1 which I'm assuming is normal. I went through and changed the numbers and saw the difficulty change on the save/load screen
2=hard
3=devil
4=hell

I'm just wondering, do I unlock the ability to adjust the difficulty setting later or is this an oversight on the game's part? I just beat the first boss of the third floor in the first dungeon.