Well,having never played a rogue game myself,i can't really say if this game's difficulty is high in regards to that or not. Having said that,the game has a little bit of a learning curve,but once you master it,it becomes incredibly easy. Granted,you should always pack a back-up option for whenever you enter a new floor,incase the RNG decides to screw you over and throw you into a wide open room with several of the girls. Always keep a sleeping or confusion potion on you for these "oh shit" moments,and target one of the girls always (never waste them on fodder enemies!)
The first level is supposed to be near-impossible. You're supposed to die pretty much. Even if you managed to clear out the entire level after reaching the end, the enemies will respawn and murderize you in the end anyways.
Here's my save folder for ver 0.09 with all soul shop upgrades purchased,and some very well crafted weapons,especially in particular,stored in the chest. This save also has the one H-scene memory and the arena with all the current existing girls unlocked. Have fun.
(Try not to use this save until you've at least played the game a bit though,lest you risk ruining the gameplay experience of building up from scratch. Part of the fun,in my opinion,is seeing the progress of you getting steadily stronger.)